[PATCH] docs/conf.py: Cope with removal of language=None in Sphinx 5.0.0

[Akira Yokosawa <akiyks@gmail.com>]

One of the changes in Sphinx 5.0.0 [1] says [sic]:

    5.0.0 final

     - #10474: language does not accept None as it value.
       The default value of language becomes to 'en' now.

[1]: https://www.sphinx-doc.org/en/master/changes.html#release-5-0-0-released-may-30-2022

It results in a new warning from Sphinx 5.0.0 [sic]:

    WARNING: Invalid configuration value found: 'language = None'.
    Update your configuration to a valid langauge code. Falling
    back to 'en' (English).

Silence the warning by using 'en'.
It works with all the Sphinx versions required for building
kernel documentation (1.7.9 or later).

Signed-off-by: Akira Yokosawa <akiyks@gmail.com>
---
 Documentation/conf.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/Documentation/conf.py b/Documentation/conf.py
index 072ee31a301d..934727e23e0e 100644
--- a/Documentation/conf.py
+++ b/Documentation/conf.py
@@ -161,7 +161,7 @@ finally:
 #
 # This is also used if you do content translation via gettext catalogs.
 # Usually you set "language" from the command line for these cases.
-language = None
+language = 'en'
 
 # There are two options for replacing |today|: either, you set today to some
 # non-false value, then it is used:

base-commit: b86f46d5ce3e7497930be931a9a9e57480f0baff
-- 
2.25.1