update make specs

Author: juhuntenburg

nipype/interfaces/freesurfer/tests/test_auto_Tkregister2.py

@@ -27,8 +27,7 @@ def test_Tkregister2_inputs():
     subject_id=dict(argstr='--s %s',
     mandatory=True,
     ),
-    subjects_dir=dict(argstr='--sd %s',
-    ),
+    subjects_dir=dict(),
     terminal_output=dict(mandatory=True,
     nohash=True,
     ),