ipc/sem.c: change perform_atomic_semop parameters

Right now, perform_atomic_semop gets the content of sem_queue as
individual fields.  Changes that, instead pass a pointer to sem_queue.

This is a preparation for the next patch: it uses sem_queue to store the
reason why a task must sleep.

Signed-off-by: Manfred Spraul <manfred@colorfullife.com>
Cc: Davidlohr Bueso <davidlohr.bueso@hp.com>
Cc: Michael Kerrisk <mtk.manpages@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>