Cleanup: Remove dead code

There is no more sorting happening, so the comment is out of date
by manu reasons. If something extra is needed there it would need
to be done differently anyway.

source/blender/makesrna/intern/rna_object_force.c

@@ -532,15 +532,6 @@ static void rna_FieldSettings_dependency_update(Main *bmain, Scene *scene, Point
   else {
     Object *ob = (Object *)ptr->id.data;
 
-    /* do this before scene sort, that one checks for CU_PATH */
-#  if 0 /* XXX */
-    if (ob->type == OB_CURVE && ob->pd->forcefield == PFIELD_GUIDE) {
-      Curve *cu = ob->data;
-      cu->flag |= (CU_PATH | CU_3D);
-      do_curvebuts(B_CU3D); /* all curves too */
-    }
-#  endif
-
     rna_FieldSettings_shape_update(bmain, scene, ptr);
 
     DEG_relations_tag_update(bmain);