fix: Unrelated bbregister bug

Author: effigies

nipype/interfaces/freesurfer/preprocess.py

@@ -1975,7 +1975,7 @@ def _list_outputs(self):
                 outputs["out_fsl_file"] = op.abspath(_in.out_fsl_file)
 
         if isdefined(_in.init_cost_file):
-            if isinstance(_in.out_fsl_file, bool):
+            if isinstance(_in.init_cost_file, bool):
                 outputs["init_cost_file"] = outputs["out_reg_file"] + ".initcost"
             else:
                 outputs["init_cost_file"] = op.abspath(_in.init_cost_file)