Btrfs: Some code cleanups

Signed-off-by: Chris Mason <chris.mason@oracle.com>
diff --git a/fs/btrfs/root-tree.c b/fs/btrfs/root-tree.c
index 271dd2b..402f678 100644
--- a/fs/btrfs/root-tree.c
+++ b/fs/btrfs/root-tree.c
@@ -135,8 +135,8 @@
 		if (btrfs_root_refs(ri) != 0)
 			goto next;
 		dead_root = btrfs_read_fs_root_no_radix(root->fs_info, &key);
-		if (IS_ERR(root)) {
-			ret = PTR_ERR(root);
+		if (IS_ERR(dead_root)) {
+			ret = PTR_ERR(dead_root);
 			goto err;
 		}
 		ret = btrfs_add_dead_root(dead_root,