FIX: Set scalar_names after MapNode is defined

Author: effigies

smriprep/workflows/surfaces.py

@@ -981,11 +981,11 @@ def init_morph_grayords_wf(
     gen_cifti = pe.MapNode(
         GenerateDScalar(
             grayordinates=grayord_density,
-            scalar_name=['curv', 'sulc', 'thickness'],
         ),
         iterfield=['scalar_name', 'scalar_surfs'],
         name="gen_cifti",
     )
+    gen_cifti.inputs.scalar_name = ['curv', 'sulc', 'thickness']
 
     # fmt: off
     workflow.connect([