xfs: xfs_commit_metadata returns wrong errno

Invert it.
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Jie Liu <jeff.liu@oracle.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>

fs/xfs/xfs_export.c

@@ -237,7 +237,7 @@ xfs_fs_nfs_commit_metadata(
 
 	if (!lsn)
 		return 0;
-	return _xfs_log_force_lsn(mp, lsn, XFS_LOG_SYNC, NULL);
+	return -_xfs_log_force_lsn(mp, lsn, XFS_LOG_SYNC, NULL);
 }
 
 const struct export_operations xfs_export_operations = {