[PATCHSET v2] Fix kyber hang

[Jens Axboe <axboe@xxxxxxxxx>]

Since the wrong kyber patch was included in the first one, here's a
v2 with just that one line corrected.

First one adds the necessary sbitmap helpers for users to be able to
do add_wait_queue() and list_del(wait_entry) type operations, and
still work with the optimized wakeup checking.

Second one converts kyber to use it, fixing a hang with domain tokens.

-- 
Jens Axboe