Fix Double underscore bug in generated code

061f19a52e3c40e30add262db95cea57655b893b introduced an extra underscore
in the make_path function for un-named groups.

site_ansto/instrument/util/gen_sct.py

@@ -519,7 +519,8 @@ def make_path(MyVar):
   path = MyVar['path']
   if len(path) > 0:
     path = path.replace('/', '_')
-  path += '_' + MyVar['name']
+    path += '_'
+  path += MyVar['name']
   return path
 
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