minor refactoring

Author: robertpatrick

core/src/main/python/wlsdeploy/tool/discover/topology_discoverer.py

@@ -838,9 +838,8 @@ def _add_library(self, server_name, classpath_name):
 
         if classpath_name is None or len(classpath_name) == 0:
             _logger.fine('WLSDPLY-06626')
-            return None
-
-        if self._is_file_to_exclude_from_archive(classpath_name):
+            return_name = None
+        elif self._is_file_to_exclude_from_archive(classpath_name):
             _logger.info('WLSDPLY-06618', classpath_name, server_name, class_name=_class_name, method_name=_method_name)
             return_name = self._model_context.tokenize_path(classpath_name)
         else: