ekf2: Correct airspeed used by EKF for calibration errors

src/modules/ekf2/EKF2.hpp

@@ -207,6 +207,8 @@ private:
 	Vector3f _last_gyro_bias{};
 	Vector3f _last_mag_bias{};
 
+	float _airspeed_scale_factor{1.0f}; ///< scale factor correction applied to airspeed measurements
+
 	uORB::Subscription _airdata_sub{ORB_ID(vehicle_air_data)};
 	uORB::Subscription _airspeed_sub{ORB_ID(airspeed)};
 	uORB::Subscription _distance_sensor_sub{ORB_ID(distance_sensor)};