EKF: capture yaw innovation test failures

EKF/mag_fusion.cpp

@@ -604,6 +604,7 @@ void Ekf::fuseHeading()
 	// set the magnetometer unhealthy if the test fails
 	if (_yaw_test_ratio > 1.0f) {
 		_mag_healthy = false;
+		_sensor_fault_status.flags.reject_yaw = true;
 
 		// if we are in air we don't want to fuse the measurement
 		// we allow to use it when on the ground because the large innovation could be caused
@@ -619,6 +620,7 @@ void Ekf::fuseHeading()
 
 	} else {
 		_mag_healthy = true;
+		_sensor_fault_status.flags.reject_yaw = false;
 	}
 
 	// apply covariance correction via P_new = (I -K*H)*P