[fix]解决SPDLOG打印bug。

saturn_controller/src/saturn_controller.cpp

@@ -231,8 +231,7 @@ void SaturnController::guardianCallback(
 void SaturnController::guardianServiceCallback(
     const daystar_navigation_msgs::srv::Guardian::Request::SharedPtr request,
     daystar_navigation_msgs::srv::Guardian::Response::SharedPtr response) {
-    SPDLOG_WARN("Guardian service is called, velocity_decay_ratio: %s",\
-        request->velocity_decay_ratio.c_str());
+    SPDLOG_WARN("Guardian service is called, velocity_decay_ratio: %f", request->velocity_decay_ratio);
     if (request->velocity_decay_ratio <= 0) {
         this->guardian_velocity_decay_ratio_ = 0.0;