ifupdownaddons: modulebase: log_error will log.error or raise an exception

Ticket: None
Reviewed By: Roopa, Nikhil G
Testing Done:

Signed-off-by: Julien Fortin <julien@cumulusnetworks.com>

ifupdownaddons/modulebase.py

@@ -59,6 +59,8 @@ class moduleBase(object):
                 if ifaceobj:
                     ifaceobj.set_status(ifaceStatus.ERROR)
                 raise Exception(str)
+            else:
+                self.logger.error(str)
         else:
             pass