Plane: Add Log_Write_Radio. MASK_LOG_PM must be set for logging to occur.

ArduPlane/GCS_Mavlink.pde

@@ -1595,7 +1595,7 @@ void GCS_MAVLINK::handleMessage(mavlink_message_t* msg)
     case MAVLINK_MSG_ID_RADIO:
     case MAVLINK_MSG_ID_RADIO_STATUS:
     {
-        handle_radio_status(msg);
+        handle_radio_status(msg, DataFlash, should_log(MASK_LOG_PM));
         break;
     }