AP_NavEKF: getHeightControlLimit modifies height on success

libraries/AP_NavEKF/AP_NavEKF.cpp

@@ -5045,10 +5045,10 @@ void NavEKF::detectOptFlowTakeoff(void)
 // this is needed to ensure the vehicle does not fly too high when using optical flow navigation
 bool NavEKF::getHeightControlLimit(float &height) const
 {
-    // If are doing optical flow nav, ensure the height above ground is within range finder limits after accounting for vehicle tilt and control errors
-    height = max(float(_rng.max_distance_cm()) * 0.007f - 1.0f, 1.0f);
     // only ask for limiting if we are doing optical flow navigation
     if (_fusionModeGPS == 3) {
+        // If are doing optical flow nav, ensure the height above ground is within range finder limits after accounting for vehicle tilt and control errors
+        height = max(float(_rng.max_distance_cm()) * 0.007f - 1.0f, 1.0f);
         return true;
     } else {
         return false;