block: initialize current->bio_list[1] in __submit_bio_noacct_mq

bio_alloc_bioset references current->bio_list[1], so we need to
initialize it for the blk-mq submission path as well.

Fixes: ff93ea0 ("block: shortcut __submit_bio_noacct for blk-mq drivers")
Reported-by: Qian Cai <cai@lca.pw>
Reported-by: Naresh Kamboju <naresh.kamboju@linaro.org>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Tested-by: Naresh Kamboju <naresh.kamboju@linaro.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block/blk-core.c

@@ -1155,11 +1155,10 @@ static blk_qc_t __submit_bio_noacct(struct bio *bio)
 static blk_qc_t __submit_bio_noacct_mq(struct bio *bio)
 {
 	struct gendisk *disk = bio->bi_disk;
-	struct bio_list bio_list;
+	struct bio_list bio_list[2] = { };
 	blk_qc_t ret = BLK_QC_T_NONE;
 
-	bio_list_init(&bio_list);
-	current->bio_list = &bio_list;
+	current->bio_list = bio_list;
 
 	do {
 		WARN_ON_ONCE(bio->bi_disk != disk);
@@ -1174,7 +1173,7 @@ static blk_qc_t __submit_bio_noacct_mq(struct bio *bio)
 		}
 
 		ret = blk_mq_submit_bio(bio);
-	} while ((bio = bio_list_pop(&bio_list)));
+	} while ((bio = bio_list_pop(&bio_list[0])));
 
 	current->bio_list = NULL;
 	return ret;