fix: typo use thread_priority (backport #1844) (#1847)

controller_manager/src/ros2_control_node.cpp

@@ -68,7 +68,7 @@ int main(int argc, char ** argv)
         {
           RCLCPP_INFO(
             cm->get_logger(), "Successful set up FIFO RT scheduling policy with priority %i.",
-            kSchedPriority);
+            thread_priority);
         }
       }
       else