fix(diagnostic_graph_aggregator): fix uselessOverride warning

Signed-off-by: Ryuta Kambe <ryuta.kambe@tier4.jp>

Author: veqcc

Diff for: system/diagnostic_graph_aggregator/src/common/graph/units.cpp

@@ -151,16 +151,6 @@ void MaxUnit::update_status()
   status_.level = std::min(level, DiagnosticStatus::ERROR);
 }
 
-void ShortCircuitMaxUnit::update_status()
-{
-  // TODO(Takagi, Isamu): update link flags.
-  DiagnosticLevel level = DiagnosticStatus::OK;
-  for (const auto & link : links_) {
-    level = std::max(level, link->child()->level());
-  }
-  status_.level = std::min(level, DiagnosticStatus::ERROR);
-}
-
 MinUnit::MinUnit(const UnitLoader & unit) : NodeUnit(unit)
 {
   links_ = unit.children();

Diff for: system/diagnostic_graph_aggregator/src/common/graph/units.hpp

@@ -137,9 +137,6 @@ class ShortCircuitMaxUnit : public MaxUnit
 public:
   using MaxUnit::MaxUnit;
   std::string type() const override { return unit_name::short_circuit_max; }
-
-private:
-  void update_status() override;
 };
 
 class MinUnit : public NodeUnit