block, bfq: use bfq_reassign_last_bfqq() in bfq_bfqq_move()

Instead of open coding it, there are no functional changes.
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Link: https://lore.kernel.org/r/20240902130329.3787024-5-yukuai1@huaweicloud.comSigned-off-by: Jens Axboe <axboe@kernel.dk>

block/bfq-cgroup.c

@@ -679,12 +679,7 @@ void bfq_bfqq_move(struct bfq_data *bfqd, struct bfq_queue *bfqq,
 		bfq_put_idle_entity(bfq_entity_service_tree(entity), entity);
 	bfqg_and_blkg_put(old_parent);
 
-	if (entity->parent &&
-	    entity->parent->last_bfqq_created == bfqq)
-		entity->parent->last_bfqq_created = NULL;
-	else if (bfqd->last_bfqq_created == bfqq)
-		bfqd->last_bfqq_created = NULL;
-
+	bfq_reassign_last_bfqq(bfqq, NULL);
 	entity->parent = bfqg->my_entity;
 	entity->sched_data = &bfqg->sched_data;
 	/* pin down bfqg and its associated blkg  */

block/bfq-iosched.c

@@ -3097,8 +3097,8 @@ static void bfq_bfqq_save_state(struct bfq_queue *bfqq)
 }
 
 
-static void
-bfq_reassign_last_bfqq(struct bfq_queue *cur_bfqq, struct bfq_queue *new_bfqq)
+void bfq_reassign_last_bfqq(struct bfq_queue *cur_bfqq,
+			    struct bfq_queue *new_bfqq)
 {
 	if (cur_bfqq->entity.parent &&
 	    cur_bfqq->entity.parent->last_bfqq_created == cur_bfqq)

block/bfq-iosched.h

@@ -1156,6 +1156,8 @@ void bfq_del_bfqq_busy(struct bfq_queue *bfqq, bool expiration);
 void bfq_add_bfqq_busy(struct bfq_queue *bfqq);
 void bfq_add_bfqq_in_groups_with_pending_reqs(struct bfq_queue *bfqq);
 void bfq_del_bfqq_in_groups_with_pending_reqs(struct bfq_queue *bfqq);
+void bfq_reassign_last_bfqq(struct bfq_queue *cur_bfqq,
+			    struct bfq_queue *new_bfqq);
 
 /* --------------- end of interface of B-WF2Q+ ---------------- */