added missing const keyword

src/modules/vtol_att_control/vtol_att_control_main.cpp

@@ -510,7 +510,7 @@ VtolAttitudeControl::is_fixed_wing_requested()
  * Abort front transition
  */
 void
-VtolAttitudeControl::abort_front_transition(char *reason)
+VtolAttitudeControl::abort_front_transition(const char *reason)
 {
 	if (!_abort_front_transition) {
 		mavlink_log_critical(&_mavlink_log_pub, "Abort: %s", reason);

src/modules/vtol_att_control/vtol_att_control_main.h

@@ -110,7 +110,7 @@ public:
 
 	int start();	/* start the task and return OK on success */
 	bool is_fixed_wing_requested();
-	void abort_front_transition(char *reason);
+	void abort_front_transition(const char *reason);
 
 	struct vehicle_attitude_s 			*get_att() {return &_v_att;}
 	struct vehicle_attitude_setpoint_s		*get_att_sp() {return &_v_att_sp;}