[PATCH] zloop: fix the error code in the blk_mq_alloc_disk message

[shao.mingyin]

From: Shao Mingyin <shao.mingyin@xxxxxxxxxx>

When blk_mq_alloc_disk() fails, "ret" still holds the zero returned by the
preceding blk_mq_alloc_tag_set() call, so the error message always reports
"err=0".  Save PTR_ERR(zlo->disk) in "ret" before printing it, like the
blk_mq_alloc_tag_set() and add_disk() failure paths do.

Fixes: eb0570c7df23 ("block: new zoned loop block device driver")
Signed-off-by: Shao Mingyin <shao.mingyin@xxxxxxxxxx>
---
diff --git a/drivers/block/zloop.c b/drivers/block/zloop.c
index 9145e0f98d56..b7cfd5a39f16 100644
--- a/drivers/block/zloop.c
+++ b/drivers/block/zloop.c
@@ -1343,8 +1343,8 @@ static int zloop_ctl_add(struct zloop_options *opts)

 	zlo->disk = blk_mq_alloc_disk(&zlo->tag_set, &lim, zlo);
 	if (IS_ERR(zlo->disk)) {
-		pr_err("blk_mq_alloc_disk failed (err=%d)\n", ret);
 		ret = PTR_ERR(zlo->disk);
+		pr_err("blk_mq_alloc_disk failed (err=%d)\n", ret);
 		goto out_cleanup_tags;
 	}
 	zlo->disk->flags = GENHD_FL_NO_PART;