When looping call fails do not log the exception trace

This makes debugging terribly difficult when there are random
legitimate errors, for example a file is not found.

Change-Id: Iec76b95a70552de8e27683c0ea388b55b519db9f

oslo_vmware/common/loopingcall.py

@@ -85,8 +85,9 @@ class FixedIntervalLoopingCall(LoopingCallBase):
             except LoopingCallDone as e:
                 self.stop()
                 done.send(e.retvalue)
-            except Exception:
-                LOG.exception('in fixed duration looping call')
+            except Exception as e:
+                LOG.error('in fixed duration looping call. Error: %s',
+                          str(e))
                 done.send_exception(*sys.exc_info())
                 return
             else: