less verbose origins on interface enable/disable

Change-Id: Ia59b3e6a9617f1b9e8dc0c488846a9fb0ec8f566
diff --git a/src/osmo_gsm_tester/ofono_client.py b/src/osmo_gsm_tester/ofono_client.py
index bb044ff7..5b7d0d2 100644
--- a/src/osmo_gsm_tester/ofono_client.py
+++ b/src/osmo_gsm_tester/ofono_client.py
@@ -145,11 +145,9 @@
         removals = self._interfaces - now
         self._interfaces = now
         for iface in removals:
-            with log.Origin('modem.disable(%s)' % iface):
-                self._on_interface_disabled(iface)
+            self._on_interface_disabled(iface)
         for iface in additions:
-            with log.Origin('modem.enable(%s)' % iface):
-                self._on_interface_enabled(iface)
+            self._on_interface_enabled(iface)
 
     def _on_interface_enabled(self, interface_name):
         self.dbg('Interface enabled:', interface_name)