Copter: fix ignore pilot yaw option for guided

ArduCopter/mode_guided.cpp

@@ -516,7 +516,7 @@ void ModeGuided::posvel_control_run()
     // process pilot's yaw input
     float target_yaw_rate = 0;
 
-    if (!copter.failsafe.radio && ((copter.g2.auto_options & (uint32_t)Options::IgnorePilotYaw) == 0)) {
+    if (!copter.failsafe.radio && use_pilot_yaw()) {
         // get pilot's desired yaw rate
         target_yaw_rate = get_pilot_desired_yaw_rate(channel_yaw->get_control_in());
         if (!is_zero(target_yaw_rate)) {