EKF: remove un-used airspeed health class variable

Airspeed rejection now is captured in _sensor_fault_status

EKF/airspeed_fusion.cpp

@@ -138,12 +138,10 @@ void Ekf::fuseAirspeed()
 
 		// If the innovation consistency check fails then don't fuse the sample and indicate bad airspeed health
 		if (_tas_test_ratio > 1.0f) {
-			_airspeed_healthy = false;
 			_sensor_fault_status.flags.reject_airspeed = true;
 			return;
 		}
 		else {
-			_airspeed_healthy = true;
 			_sensor_fault_status.flags.reject_airspeed = false;
 		}
 

EKF/estimator_interface.cpp

@@ -57,7 +57,6 @@ EstimatorInterface::EstimatorInterface():
 	_gps_speed_valid(false),
 	_gps_origin_eph(0.0f),
 	_gps_origin_epv(0.0f),
-	_airspeed_healthy(false),
 	_yaw_test_ratio(0.0f),
 	_time_last_imu(0),
 	_time_last_gps(0),

EKF/estimator_interface.h

@@ -259,7 +259,6 @@ protected:
 	float _gps_origin_epv; // vertical position uncertainty of the GPS origin
 	struct map_projection_reference_s _pos_ref;    // Contains WGS-84 position latitude and longitude (radians)
 
-	bool _airspeed_healthy;		// computed by airspeed innovation test
 	float _yaw_test_ratio;          // yaw innovation consistency check ratio
 	float _mag_test_ratio[3];       // magnetometer XYZ innovation consistency check ratios
 	float _vel_pos_test_ratio[6];   // velocity and position innovation consistency check ratios