block: correct stale comment in rq_qos_wait

The rq_qos_wait calls common wake-up function rq_qos_wake_function to get
token. Just replace stale wbt_wake_function with rq_qos_wake_function in
comment.
Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com>
Acked-by: Tejun Heo <tj@kernel.org>
Link: https://lore.kernel.org/r/20230914091508.36232-1-shikemeng@huaweicloud.comSigned-off-by: Jens Axboe <axboe@kernel.dk>

block/blk-rq-qos.c

@@ -270,7 +270,7 @@ void rq_qos_wait(struct rq_wait *rqw, void *private_data,
 			finish_wait(&rqw->wait, &data.wq);
 
 			/*
-			 * We raced with wbt_wake_function() getting a token,
+			 * We raced with rq_qos_wake_function() getting a token,
 			 * which means we now have two. Put our local token
 			 * and wake anyone else potentially waiting for one.
 			 */