vtol_att_control: apply multicopter takeoff hotfix also for vtol (#12250)

Please see reference:
https://github.com/PX4/Firmware/issues/12171

src/modules/mc_att_control/mc_att_control_main.cpp

@@ -521,7 +521,7 @@ MulticopterAttitudeControl::control_attitude()
 {
 	vehicle_attitude_setpoint_poll();
 
-	// reinitialize the setpoint while not armed to make sure no value from the last flight is still kept
+	// reinitialize the setpoint while not armed to make sure no value from the last mode or flight is still kept
 	if (!_v_control_mode.flag_armed) {
 		Quatf().copyTo(_v_att_sp.q_d);
 		Vector3f().copyTo(_v_att_sp.thrust_body);

src/modules/vtol_att_control/vtol_att_control_main.cpp

@@ -48,6 +48,9 @@
  */
 #include "vtol_att_control_main.h"
 #include <systemlib/mavlink_log.h>
+#include <matrix/matrix/math.hpp>
+
+using namespace matrix;
 
 namespace VTOL_att_control
 {
@@ -701,6 +704,14 @@ void VtolAttitudeControl::task_main()
 			_vtol_type->fill_actuator_outputs();
 		}
 
+		// reinitialize the setpoint while not armed to make sure no value from the last mode or flight is still kept
+		if (!_v_control_mode.flag_armed) {
+			Quatf().copyTo(_mc_virtual_att_sp.q_d);
+			Vector3f().copyTo(_mc_virtual_att_sp.thrust_body);
+			Quatf().copyTo(_v_att_sp.q_d);
+			Vector3f().copyTo(_v_att_sp.thrust_body);
+		}
+
 		/* Only publish if the proper mode(s) are enabled */
 		if (_v_control_mode.flag_control_attitude_enabled ||
 		    _v_control_mode.flag_control_rates_enabled ||