EKF: Use fixed wing status flag in MAG_FUSE_TYPE_AUTOFW logic

EKF/mag_fusion.cpp

@@ -165,12 +165,11 @@ void Ekf::fuseMag()
 
 	/*
 	When flying as a fixed wing aircraft, a misaligned magnetometer can cause an error in pitch/roll and accel bias estimates.
-	When MAG_FUSE_TYPE_AUTOFW is selected and the vehicle is flying as a fixed wing as detected by the use of wind estimation
-	and current airspeed estimates, then magnetometer fusion is only allowed to access the magnetic field states.
+	When MAG_FUSE_TYPE_AUTOFW is selected and the vehicle is flying as a fixed wing, then magnetometer fusion is only allowed
+	to access the magnetic field states.
 	*/
 	_control_status.flags.update_mag_states_only = (_params.mag_fusion_type == MAG_FUSE_TYPE_AUTOFW)
-			&& _control_status.flags.wind
-			&& (_time_last_imu - _time_last_airspeed < 1E7);
+			&& _control_status.flags.fixed_wing;
 
 	// update the states and covariance using sequential fusion of the magnetometer components
 	for (uint8_t index = 0; index <= 2; index++) {