blk-mq: improve error handling in blk_mq_alloc_rq_map()

Use goto-style error handling like we do elsewhere in the kernel.
Signed-off-by: Jinlong Chen <nickyc975@zju.edu.cn>
Link: https://lore.kernel.org/r/bbbc2d9b17b137798c7fb92042141ca4cbbc58cc.1667356813.git.nickyc975@zju.edu.cnSigned-off-by: Jens Axboe <axboe@kernel.dk>

block/blk-mq.c

@@ -3305,21 +3305,22 @@ static struct blk_mq_tags *blk_mq_alloc_rq_map(struct blk_mq_tag_set *set,
 	tags->rqs = kcalloc_node(nr_tags, sizeof(struct request *),
 				 GFP_NOIO | __GFP_NOWARN | __GFP_NORETRY,
 				 node);
-	if (!tags->rqs) {
-		blk_mq_free_tags(tags);
-		return NULL;
-	}
+	if (!tags->rqs)
+		goto err_free_tags;
 
 	tags->static_rqs = kcalloc_node(nr_tags, sizeof(struct request *),
 					GFP_NOIO | __GFP_NOWARN | __GFP_NORETRY,
 					node);
-	if (!tags->static_rqs) {
+	if (!tags->static_rqs)
+		goto err_free_rqs;
+
+	return tags;
+
+err_free_rqs:
 	kfree(tags->rqs);
+err_free_tags:
 	blk_mq_free_tags(tags);
 	return NULL;
-	}
-
-	return tags;
 }
 
 static int blk_mq_init_request(struct blk_mq_tag_set *set, struct request *rq,