block: remove queue_lockdep_assert_held

The only remaining user unconditionally drops and reacquires the lock,
which means we really don't need any additional (conditional) annotation.
Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block/blk-throttle.c

@@ -2353,7 +2353,6 @@ void blk_throtl_drain(struct request_queue *q)
 	struct bio *bio;
 	int rw;
 
-	queue_lockdep_assert_held(q);
 	rcu_read_lock();
 
 	/*

block/blk.h

@@ -35,19 +35,6 @@ extern struct kmem_cache *blk_requestq_cachep;
 extern struct kobj_type blk_queue_ktype;
 extern struct ida blk_queue_ida;
 
-/*
- * @q->queue_lock is set while a queue is being initialized. Since we know
- * that no other threads access the queue object before @q->queue_lock has
- * been set, it is safe to manipulate queue flags without holding the
- * queue_lock if @q->queue_lock == NULL. See also blk_alloc_queue_node() and
- * blk_init_allocated_queue().
- */
-static inline void queue_lockdep_assert_held(struct request_queue *q)
-{
-	if (q->queue_lock)
-		lockdep_assert_held(q->queue_lock);
-}
-
 static inline struct blk_flush_queue *
 blk_get_flush_queue(struct request_queue *q, struct blk_mq_ctx *ctx)
 {