Plane: Handle NAV_CONTROLLER_OUTPUT.wp_dist overflowing

ArduPlane/GCS_Mavlink.cpp

@@ -199,7 +199,7 @@ void Plane::send_nav_controller_output(mavlink_channel_t chan)
         nav_pitch_cd * 0.01f,
         nav_controller->nav_bearing_cd() * 0.01f,
         nav_controller->target_bearing_cd() * 0.01f,
-        auto_state.wp_distance,
+        MIN(auto_state.wp_distance, UINT16_MAX),
         altitude_error_cm * 0.01f,
         airspeed_error * 100,
         nav_controller->crosstrack_error());