modify: delete is_active() method

Signed-off-by: TetsuKawa <kawaguchitnon@icloud.com>

Author: TetsuKawa

system/cgroup_setter/config/cgroup.yaml

@@ -2,3 +2,4 @@ base_path: "/sys/fs/cgroup"
 settings:
   - directory: "autoware/system_monitor"
     search_word: 
+      - "__node:=system_monitor_container"

system/cgroup_setter/src/cgroup_setter.cpp

@@ -84,7 +84,7 @@ void CgroupSetter::checkCgroup(diagnostic_updater::DiagnosticStatusWrapper & sta
         }
     }
     if (allOK) {
-        if (timer_->is_active()) timer->cancel();
+        timer_->cancel();
         stat.summary(diagnostic_msgs::msg::DiagnosticStatus::OK, "All processes are added to cgroup.");
     } else {
         stat.summary(diagnostic_msgs::msg::DiagnosticStatus::WARN, "Some processes are not added to cgroup.");