FailureDetector - Add is_failure() function to simplify the interface; the user does not need to check the bitmask

src/modules/commander/Commander.cpp

@@ -2223,14 +2223,14 @@ Commander::run()
 		    !_flight_termination_triggered &&
 		    !status_flags.circuit_breaker_flight_termination_disabled) {
 
-			if (status.failure_detector_status != 0) {
+			if (_failure_detector.is_failure()) {
 
 				armed.force_failsafe = true;
 				status_changed = true;
 
 				_flight_termination_triggered = true;
 
-				mavlink_log_critical(&mavlink_log_pub, "Attitude failure detected: force failsafe");
+				mavlink_log_critical(&mavlink_log_pub, "Critical failure detected: terminate flight");
 				set_tune_override(TONE_PARACHUTE_RELEASE_TUNE);
 			}
 		}

src/modules/commander/failure_detector/FailureDetector.hpp

@@ -70,7 +70,8 @@ public:
 
 	bool update();
 
-	uint8_t get_status() const {return _status;}
+	uint8_t get_status() const { return _status; }
+	bool is_failure() const { return (_status == FAILURE_NONE) ? false : true; }
 
 private: