drm/sched: Fix drm_sched_fini() docu generation

drm/sched: Fix drm_sched_fini() docu generation

Commit baf4afc5831438 ("drm/sched: Improve teardown documentation")
added a list of drm_sched_fini()'s problems. The list triggers htmldocs
warning (but renders correctly in htmldocs output):

Documentation/gpu/drm-mm:571: ./drivers/gpu/drm/scheduler/sched_main.c:1359: ERROR: Unexpected indentation.

Separate the list from the preceding paragraph by a blank line to fix
the warning. While at it, also end the aforementioned paragraph by a
colon.

Fixes: baf4afc58314 ("drm/sched: Improve teardown documentation")
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Closes: https://lore.kernel.org/r/20241108175655.6d3fcfb7@canb.auug.org.au/
Signed-off-by: Bagas Sanjaya <bagasdotme@gmail.com>
[phasta: Adjust commit message]
Signed-off-by: Philipp Stanner <phasta@kernel.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20241217034915.62594-1-bagasdotme@gmail.com