blk-mq: Drop explicit timeout sync in hotplug

After commit 287922eb0b ("block: defer timeouts to a workqueue"),
deleting the timeout work after freezing the queue shouldn't be
necessary, since the synchronization is already enforced by the
acquisition of a q_usage_counter reference in blk_mq_timeout_work.

Signed-off-by: Gabriel Krisman Bertazi <krisman@linux.vnet.ibm.com>
Reviewed-by: Ming Lei <ming.lei@canonical.com>
Signed-off-by: Jens Axboe <axboe@fb.com>

block/blk-mq.c

@@ -2220,16 +2220,9 @@ static void blk_mq_queue_reinit_work(void)
 	 */
 	list_for_each_entry(q, &all_q_list, all_q_node)
 		blk_mq_freeze_queue_start(q);
-	list_for_each_entry(q, &all_q_list, all_q_node) {
+	list_for_each_entry(q, &all_q_list, all_q_node)
 		blk_mq_freeze_queue_wait(q);
 
-		/*
-		 * timeout handler can't touch hw queue during the
-		 * reinitialization
-		 */
-		del_timer_sync(&q->timeout);
-	}
-
 	list_for_each_entry(q, &all_q_list, all_q_node)
 		blk_mq_queue_reinit(q, &cpuhp_online_new);