advertise esc_status where is publishes

- esc_status is an optional logging topic resulting in it not being
logged if it doesn't get advertise -> Add advertise where applicable

src/drivers/uavcan/actuators/esc.cpp

@@ -64,6 +64,8 @@ UavcanEscController::init()
 		return res;
 	}
 
+	_esc_status_pub.advertise();
+
 	return res;
 }