io-wq: ensure that hash wait lock is IRQ disabling

A previous commit removed the IRQ safety of the worker and wqe locks,
but that left one spot of the hash wait lock now being done without
already having IRQs disabled.

Ensure that we use the right locking variant for the hashed waitqueue
lock.

Fixes: a9a4aa9f ("io-wq: wqe and worker locks no longer need to be IRQ safe")
Signed-off-by: Jens Axboe <axboe@kernel.dk>