[PATCH] kernel/cpuset.c, mutex conversion

convert cpuset.c's callback_sem and manage_sem to mutexes.
Build and boot tested by Ingo.
Build, boot, unit and stress tested by pj.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Paul Jackson <pj@sgi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>