kcsan: fix a kernel-doc warning

kcsan: fix a kernel-doc warning

One of the kernel-doc markups there have two "note" sections:

	./include/linux/kcsan-checks.h:346: warning: duplicate section name 'Note'

While this is not the case here, duplicated sections can cause
build issues on Sphinx. So, let's change the notes section
to use, instead, a list for those 2 notes at the same function.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Acked-by: Marco Elver <elver@google.com>
Link: https://lore.kernel.org/r/20f7995fab2ba85ce723203e9a7c822a55cca2af.1592895969.git.mchehab+huawei@kernel.org
Signed-off-by: Jonathan Corbet <corbet@lwn.net>