docs: sphinx/kernel_abi: adjust coding style

Make pylint and flake8 happier with this module's coding style

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Link: https://lore.kernel.org/r/02a9ec0fab61e4c94b9c2ff555bc0e9d93f59100.1739182025.git.mchehab+huawei@kernel.org