block: call blk_exit_queue() before freeing q->stats

blk_stat_disable_accounting() is added in commit 68497092
("block: make queue stat accounting a reference"), and called in
kyber_exit_sched().

So we have to free q->stats after elevator is unloaded from
blk_exit_queue() in blk_release_queue(). Otherwise kernel panic
is caused.

Fixes: 68497092 ("block: make queue stat accounting a reference")
Signed-off-by: NMing Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/20211221040436.1333880-1-ming.lei@redhat.comSigned-off-by: NJens Axboe <axboe@kernel.dk>

block/blk-sysfs.c

@@ -791,11 +791,11 @@ static void blk_release_queue(struct kobject *kobj)
 		blk_stat_remove_callback(q, q->poll_cb);
 	blk_stat_free_callback(q->poll_cb);
 
+	blk_exit_queue(q);
+
 	blk_free_queue_stats(q->stats);
 	kfree(q->poll_stat);
 
-	blk_exit_queue(q);
-
 	blk_queue_free_zone_bitmaps(q);
 
 	if (queue_is_mq(q))