EKF: upgrade some events from into to warning status

EKF/control.cpp

@@ -336,7 +336,7 @@ void Ekf::controlExternalVisionFusion()
 
 		// Turn off EV fusion mode if no data has been received
 		stopEvFusion();
-		ECL_INFO_TIMESTAMPED("vision data stopped");
+		ECL_WARN_TIMESTAMPED("vision data stopped");
 
 	}
 }

EKF/ekf_helper.cpp

@@ -1611,7 +1611,7 @@ bool Ekf::resetYawToEKFGSF()
 		// stop using the magnetometer in the main EKF otherwise it's fusion could drag the yaw around
 		// and cause another navigation failure
 		_control_status.flags.mag_fault = true;
-		ECL_INFO_TIMESTAMPED("Emergency yaw reset - mag use stopped");
+		ECL_WARN_TIMESTAMPED("Emergency yaw reset - mag use stopped");
 	}
 
 	return true;