vehicle_rates_setpoint: log wheel controller yaw rate on common yaw rate channel

msg/vehicle_rates_setpoint.msg

@@ -5,9 +5,6 @@ float32 roll		# [rad/s] roll rate setpoint
 float32 pitch		# [rad/s] pitch rate setpoint
 float32 yaw		# [rad/s] yaw rate setpoint
 
-# [rad/s] yaw rate setpoint the wheel attempts to track (the wheel controller has different gains than the yaw controller)
-float32 yaw_via_wheel
-
 # For clarification: For multicopters thrust_body[0] and thrust[1] are usually 0 and thrust[2] is the negative throttle demand.
 # For fixed wings thrust_x is the throttle demand and thrust_y, thrust_z will usually be zero.
 float32[3] thrust_body	# Normalized thrust command in body NED frame [-1,1]

src/modules/fw_att_control/FixedwingAttitudeControl.cpp

@@ -601,8 +601,7 @@ void FixedwingAttitudeControl::Run()
 				 */
 				_rates_sp.roll = _roll_ctrl.get_desired_bodyrate();
 				_rates_sp.pitch = _pitch_ctrl.get_desired_bodyrate();
-				_rates_sp.yaw = _yaw_ctrl.get_desired_bodyrate();
-				_rates_sp.yaw_via_wheel = _wheel_ctrl.get_desired_rate();
+				_rates_sp.yaw = (wheel_control) ? _wheel_ctrl.get_desired_rate() : _yaw_ctrl.get_desired_bodyrate();
 
 				_rates_sp.timestamp = hrt_absolute_time();