Fix severe warning from class loader in servo (#3577)

* Add class loader member variable instead of  creating on stack

* Fix formatting to satisfy clang

---------

Co-authored-by: AndyZe <andyz@utexas.edu>
Co-authored-by: Nathan Brooks <nathanbrooks@picknik.ai>
(cherry picked from commit 92654dd)

Author: 3 people

moveit_ros/moveit_servo/include/moveit_servo/servo.hpp

@@ -229,6 +229,9 @@ class Servo
   std::atomic<double> collision_velocity_scale_ = 1.0;
   std::unique_ptr<CollisionMonitor> collision_monitor_;
 
+  // Plugin loader
+  std::unique_ptr<pluginlib::ClassLoader<online_signal_smoothing::SmoothingBaseClass>> smoother_loader_;
+
   // Pointer to the (optional) smoothing plugin.
   pluginlib::UniquePtr<online_signal_smoothing::SmoothingBaseClass> smoother_ = nullptr;
 

moveit_ros/moveit_servo/src/servo.cpp

@@ -139,9 +139,9 @@ void Servo::setSmoothingPlugin()
   // Load the smoothing plugin
   try
   {
-    pluginlib::ClassLoader<online_signal_smoothing::SmoothingBaseClass> smoothing_loader(
+    smoother_loader_ = std::make_unique<pluginlib::ClassLoader<online_signal_smoothing::SmoothingBaseClass>>(
         "moveit_core", "online_signal_smoothing::SmoothingBaseClass");
-    smoother_ = smoothing_loader.createUniqueInstance(servo_params_.smoothing_filter_plugin_name);
+    smoother_ = smoother_loader_->createUniqueInstance(servo_params_.smoothing_filter_plugin_name);
   }
   catch (pluginlib::PluginlibException& ex)
   {