mutex: Fix annotations to include it in kernel-locking docbook
Fix kernel-doc notation in linux/mutex.h and kernel/mutex.c,
then add these 2 files to the kernel-locking docbook as the
Mutex API reference chapter.
Add one API function to mutex-design.txt and correct a typo in
Signed-off-by: Randy Dunlap <email@example.com>
Cc: Rusty Russell <firstname.lastname@example.org>
Signed-off-by: Ingo Molnar <email@example.com>