docs: kdoc: handle the obsolescensce of docutils.ErrorString()

The ErrorString() and SafeString() docutils functions were helpers meant to
ease the handling of encodings during the Python 3 transition.  There is no
real need for them after Python 3.6, and docutils 0.22 removes them,
breaking the docs build

Handle this by just injecting our own one-liner version of ErrorString(),
and removing the sole SafeString() call entirely.

Reported-by: Zhixu Liu <zhixu.liu@gmail.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Message-ID: <87ldmnv2pi.fsf@trenco.lwn.net>

1 files changed, 3 insertions, 1 deletions

diff --git a/Documentation/sphinx/maintainers_include.py b/Documentation/sphinx/maintainers_include.py
index d31cff867436..519ad18685b2 100755
--- a/Documentation/sphinx/maintainers_include.py
+++ b/Documentation/sphinx/maintainers_include.py
@@ -22,10 +22,12 @@ import re
 import os.path
 
 from docutils import statemachine
-from docutils.utils.error_reporting import ErrorString
 from docutils.parsers.rst import Directive
 from docutils.parsers.rst.directives.misc import Include
 
+def ErrorString(exc):  # Shamelessly stolen from docutils
+    return f'{exc.__class__.__name}: {exc}'
+
 __version__  = '1.0'
 
 def setup(app):