blk-mq: Remove blk_mq_cancel_requeue_work()

Since blk_mq_requeue_work() no longer restarts stopped queues
canceling requeue work is no longer needed to prevent that a
stopped queue would be restarted. Hence remove this function.

Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Cc: Mike Snitzer <snitzer@redhat.com>
Cc: Keith Busch <keith.busch@intel.com>
Cc: Hannes Reinecke <hare@suse.com>
Cc: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>

drivers/md/dm-rq.c

@@ -116,8 +116,6 @@ static void dm_mq_stop_queue(struct request_queue *q)
 	queue_flag_set(QUEUE_FLAG_STOPPED, q);
 	spin_unlock_irqrestore(q->queue_lock, flags);
 
-	/* Avoid that requeuing could restart the queue. */
-	blk_mq_cancel_requeue_work(q);
 	blk_mq_stop_hw_queues(q);
 }