rust: clean Rust 1.88.0's `clippy::uninlined_format_args` lint

Starting with Rust 1.88.0 (expected 2025-06-26) [1], `rustc` may move
back the `uninlined_format_args` to `style` from `pedantic` (it was
there waiting for rust-analyzer suppotr), and thus we will start to see
lints like:

    warning: variables can be used directly in the `format!` string
       --> rust/macros/kunit.rs:105:37
        |
    105 |         let kunit_wrapper_fn_name = format!("kunit_rust_wrapper_{}", test);
        |                                     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
        |
        = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#uninlined_format_args
    help: change this to
        |
    105 -         let kunit_wrapper_fn_name = format!("kunit_rust_wrapper_{}", test);
    105 +         let kunit_wrapper_fn_name = format!("kunit_rust_wrapper_{test}");

There is even a case that is a pure removal:

    warning: variables can be used directly in the `format!` string
      --> rust/macros/module.rs:51:13
       |
    51 |             format!("{field}={content}\0", field = field, content = content)
       |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
       |
       = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#uninlined_format_args
    help: change this to
       |
    51 -             format!("{field}={content}\0", field = field, content = content)
    51 +             format!("{field}={content}\0")

The lints all seem like nice cleanups, thus just apply them.

We may want to disable `allow-mixed-uninlined-format-args` in the future.

Cc: stable@vger.kernel.org # Needed in 6.12.y and later (Rust is pinned in older LTSs).
Link: https://github.com/rust-lang/rust-clippy/pull/14160 [1]
Acked-by: Benno Lossin <lossin@kernel.org>
Reviewed-by: Tamir Duberstein <tamird@gmail.com>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Link: https://lore.kernel.org/r/20250502140237.1659624-6-ojeda@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>

3 files changed, 10 insertions, 24 deletions

diff --git a/rust/macros/kunit.rs b/rust/macros/kunit.rs
index 4f553ecf40c0..99ccac82edde 100644
--- a/rust/macros/kunit.rs
+++ b/rust/macros/kunit.rs
@@ -15,10 +15,7 @@ pub(crate) fn kunit_tests(attr: TokenStream, ts: TokenStream) -> TokenStream {
     }
 
     if attr.len() > 255 {
-        panic!(
-            "The test suite name `{}` exceeds the maximum length of 255 bytes",
-            attr
-        )
+        panic!("The test suite name `{attr}` exceeds the maximum length of 255 bytes")
     }
 
     let mut tokens: Vec<_> = ts.into_iter().collect();
@@ -102,16 +99,14 @@ pub(crate) fn kunit_tests(attr: TokenStream, ts: TokenStream) -> TokenStream {
     let mut kunit_macros = "".to_owned();
     let mut test_cases = "".to_owned();
     for test in &tests {
-        let kunit_wrapper_fn_name = format!("kunit_rust_wrapper_{}", test);
+        let kunit_wrapper_fn_name = format!("kunit_rust_wrapper_{test}");
         let kunit_wrapper = format!(
-            "unsafe extern \"C\" fn {}(_test: *mut kernel::bindings::kunit) {{ {}(); }}",
-            kunit_wrapper_fn_name, test
+            "unsafe extern \"C\" fn {kunit_wrapper_fn_name}(_test: *mut kernel::bindings::kunit) {{ {test}(); }}"
         );
         writeln!(kunit_macros, "{kunit_wrapper}").unwrap();
         writeln!(
             test_cases,
-            "    kernel::kunit::kunit_case(kernel::c_str!(\"{}\"), {}),",
-            test, kunit_wrapper_fn_name
+            "    kernel::kunit::kunit_case(kernel::c_str!(\"{test}\"), {kunit_wrapper_fn_name}),"
         )
         .unwrap();
     }
diff --git a/rust/macros/module.rs b/rust/macros/module.rs
index a9418fbc9b44..2f66107847f7 100644
--- a/rust/macros/module.rs
+++ b/rust/macros/module.rs
@@ -48,7 +48,7 @@ impl<'a> ModInfoBuilder<'a> {
             )
         } else {
             // Loadable modules' modinfo strings go as-is.
-            format!("{field}={content}\0", field = field, content = content)
+            format!("{field}={content}\0")
         };
 
         write!(
@@ -126,10 +126,7 @@ impl ModuleInfo {
             };
 
             if seen_keys.contains(&key) {
-                panic!(
-                    "Duplicated key \"{}\". Keys can only be specified once.",
-                    key
-                );
+                panic!("Duplicated key \"{key}\". Keys can only be specified once.");
             }
 
             assert_eq!(expect_punct(it), ':');
@@ -143,10 +140,7 @@ impl ModuleInfo {
                 "license" => info.license = expect_string_ascii(it),
                 "alias" => info.alias = Some(expect_string_array(it)),
                 "firmware" => info.firmware = Some(expect_string_array(it)),
-                _ => panic!(
-                    "Unknown key \"{}\". Valid keys are: {:?}.",
-                    key, EXPECTED_KEYS
-                ),
+                _ => panic!("Unknown key \"{key}\". Valid keys are: {EXPECTED_KEYS:?}."),
             }
 
             assert_eq!(expect_punct(it), ',');
@@ -158,7 +152,7 @@ impl ModuleInfo {
 
         for key in REQUIRED_KEYS {
             if !seen_keys.iter().any(|e| e == key) {
-                panic!("Missing required key \"{}\".", key);
+                panic!("Missing required key \"{key}\".");
             }
         }
 
@@ -170,10 +164,7 @@ impl ModuleInfo {
         }
 
         if seen_keys != ordered_keys {
-            panic!(
-                "Keys are not ordered as expected. Order them like: {:?}.",
-                ordered_keys
-            );
+            panic!("Keys are not ordered as expected. Order them like: {ordered_keys:?}.");
         }
 
         info
diff --git a/rust/macros/paste.rs b/rust/macros/paste.rs
index 6529a387673f..cce712d19855 100644
--- a/rust/macros/paste.rs
+++ b/rust/macros/paste.rs
@@ -50,7 +50,7 @@ fn concat_helper(tokens: &[TokenTree]) -> Vec<(String, Span)> {
                 let tokens = group.stream().into_iter().collect::<Vec<TokenTree>>();
                 segments.append(&mut concat_helper(tokens.as_slice()));
             }
-            token => panic!("unexpected token in paste segments: {:?}", token),
+            token => panic!("unexpected token in paste segments: {token:?}"),
         };
     }