add method to block fallback to mission

failsafe navigation modes can use a flag in mission_result to tell the
commander to not switch back to mission

src/modules/navigator/mission.h

@@ -128,11 +128,6 @@ private:
 	 */
 	void report_mission_finished();
 
-	/**
-	 * Publish the mission result so commander and mavlink know what is going on
-	 */
-	void publish_mission_result();
-
 	control::BlockParamInt _param_onboard_enabled;
 	control::BlockParamFloat _param_takeoff_alt;
 	control::BlockParamFloat _param_dist_1wp;
@@ -145,9 +140,6 @@ private:
 	bool _need_takeoff;
 	bool _takeoff;
 
-	orb_advert_t _mission_result_pub;
-	struct mission_result_s _mission_result;
-
 	enum {
 		MISSION_TYPE_NONE,
 		MISSION_TYPE_ONBOARD,