ipc,sem: have only one list in struct sem_queue

ipc,sem: have only one list in struct sem_queue

Having only one list in struct sem_queue, and only queueing simple
semaphore operations on the list for the semaphore involved, allows us to
introduce finer grained locking for semtimedop.

Signed-off-by: Rik van Riel <[email protected]>
Acked-by: Davidlohr Bueso <[email protected]>
Cc: Chegu Vinod <[email protected]>
Cc: Emmanuel Benisty <[email protected]>
Cc: Jason Low <[email protected]>
Cc: Michel Lespinasse <[email protected]>
Cc: Peter Hurley <[email protected]>
Cc: Stanislav Kinsbursky <[email protected]>
Tested-by: Sedat Dilek <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>