module: fix comment style

Many comments in this module do not comply with the preferred multi-line
comment style as reported by 'scripts/checkpatch.pl':

WARNING: Block comments use * on subsequent lines
WARNING: Block comments use a trailing */ on a separate line

Fix those comments, along with (unreported for some reason?) the starts
of the multi-line comments not being /* on their own line...

Signed-off-by: Sergey Shtylyov <s.shtylyov@omprussia.ru>
Signed-off-by: Jessica Yu <jeyu@kernel.org>