[PATCH -next] fs/btrfs: Fix unlocking in btrfs_ref_tree_mod

[Bo YU]

It adds spin_lock() in add_block_entry() but out path does not unlock
it.

Detected by CoversityScan, CID# 1463343:(Missing unlock)

Fixes: fd708b81d972a (Btrfs: add a extent ref verify tool)
Signed-off-by: Bo YU <tsu.yubo@xxxxxxxxx>
---
fs/btrfs/ref-verify.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/fs/btrfs/ref-verify.c b/fs/btrfs/ref-verify.c
index 7887317033c9..8f644511006d 100644
--- a/fs/btrfs/ref-verify.c
+++ b/fs/btrfs/ref-verify.c
@@ -894,8 +894,10 @@ int btrfs_ref_tree_mod(struct btrfs_fs_info *fs_info,
out_unlock:
	spin_unlock(&fs_info->ref_verify_lock);
out:
-	if (ret)
+	if (ret) {
+		spin_unlock(&fs_info->ref_verify_lock);
		btrfs_clear_opt(fs_info->mount_opt, REF_VERIFY);
+	}
	return ret;
}

--
2.11.0