[PATCH] cpuset: fix return without releasing semaphore

It is wrong to acquire the semaphore and then return from
cpuset_zone_allowed without releasing it.

Signed-off-by: Bob Picco <bob.picco@hp.com>
Acked-by: Paul Jackson <pj@sgi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>