module: Fix a comment above strong_try_module_get()

The comment above strong_try_module_get() function is not true anymore.
Return values changed with commit c9a3ba55

 ("module: wait for
dependent modules doing init.").

Signed-off-by: Miroslav Benes <mbenes@suse.cz>
Link: http://lkml.kernel.org/r/alpine.LNX.2.00.1611161635330.12580@pobox.suse.cz
[jeyu@redhat.com: style fixes to make checkpatch.pl happy]
Signed-off-by: Jessica Yu <jeyu@redhat.com>