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>
diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index 34142d5..841330f 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -2529,7 +2529,7 @@
 			      struct inode *inode);
 int btrfs_orphan_add(struct btrfs_trans_handle *trans, struct inode *inode);
 int btrfs_orphan_del(struct btrfs_trans_handle *trans, struct inode *inode);
-void btrfs_orphan_cleanup(struct btrfs_root *root);
+int btrfs_orphan_cleanup(struct btrfs_root *root);
 void btrfs_orphan_pre_snapshot(struct btrfs_trans_handle *trans,
 				struct btrfs_pending_snapshot *pending,
 				u64 *bytes_to_reserve);