Correct error codes.

common/JackAPI.cpp

@@ -1385,7 +1385,7 @@ LIB_EXPORT int jack_get_cycle_times(const jack_client_t *client,
         control->ReadFrameTime(&timer);
         return timer.GetCycleTimes(current_frames, current_usecs, next_usecs, period_usecs);
     } else {
-        return 1;
+        return -1;
     }
 }
 

common/JackFrameTimer.cpp

@@ -98,7 +98,7 @@ int JackTimer::GetCycleTimes(jack_nframes_t* current_frames, jack_time_t* curren
         *period_usecs = fPeriodUsecs;
         return 0;
     } else {
-        return 1;
+        return -1;
     }
 }