Btrfs: handle errors in btrfs_orphan_cleanup

If we cannot truncate an inode for some reason we will never delete the orphan
item associated with that inode, which means that we will loop forever in
btrfs_orphan_cleanup.  Instead of doing this just return error so we fail to
mount.  It sucks, but hey it's better than hanging.  Thanks,

Signed-off-by: Josef Bacik <josef@redhat.com>

fs/btrfs/extent-tree.c

@@ -7619,7 +7619,8 @@ int btrfs_cleanup_reloc_trees(struct btrfs_root *root)
 
 	reloc_root = btrfs_read_fs_root_no_name(root->fs_info, &location);
 	BUG_ON(!reloc_root);
-	btrfs_orphan_cleanup(reloc_root);
+	ret = btrfs_orphan_cleanup(reloc_root);
+	BUG_ON(ret);
 	return 0;
 }