TauAnalysisTools: Fix cppcheck 2.14 warnings.

TauAnalysisTools: Fix cppcheck 2.14 warnings.

Prefer returning const references to members rather than copies.
Pass strings by const reference, not by value.

PhysicsAnalysis/TauID/TauAnalysisTools/Root/HelperFunctions.cxx

 /*
-  Copyright (C) 2002-2022 CERN for the benefit of the ATLAS collaboration
+  Copyright (C) 2002-2024 CERN for the benefit of the ATLAS collaboration
 */
 
 #include <fstream>
@@ -276,7 +276,7 @@ int TauAnalysisTools::getNTauDecayParticles(const xAOD::TruthParticle& xTruthTau
 }
 
 //______________________________________________________________________________
-bool TauAnalysisTools::testFileForEOFContainsCharacters(std::string sFileName)
+bool TauAnalysisTools::testFileForEOFContainsCharacters(const std::string& sFileName)
 {
   // returns true if last line in file is empty or the line starts with the
   // number sign #

PhysicsAnalysis/TauID/TauAnalysisTools/TauAnalysisTools/DiTauSelectionCuts.h

 /*
-  Copyright (C) 2002-2023 CERN for the benefit of the ATLAS collaboration
+  Copyright (C) 2002-2024 CERN for the benefit of the ATLAS collaboration
 */
 
 #ifndef TAUANALYSISTOOLS_DITAUSELECTIONCUTS_H
@@ -40,7 +40,7 @@ public:
                       asg::AcceptData& accept) = 0;
   TH1F* CreateControlPlot(const char* sName, const char* sTitle, int iBins, double dXLow, double dXUp);
 
-  std::string getName()
+  const std::string& getName()
   {
     return m_sName;
   };

PhysicsAnalysis/TauID/TauAnalysisTools/TauAnalysisTools/HelperFunctions.h

@@ -5,7 +5,7 @@
  * @brief 
  * @date 2021-02-19
  * 
- * @copyright Copyright (C) 2002-2022 CERN for the benefit of the ATLAS collaboration
+ * @copyright Copyright (C) 2002-2024 CERN for the benefit of the ATLAS collaboration
  * 
  */
 
@@ -87,7 +87,7 @@ xAOD::TauJetParameters::DecayMode getTruthDecayMode(const xAOD::TauJet& xTau);
  */
 int getNTauDecayParticles(const xAOD::TruthParticle& xTruthTau, int iPdgId, bool bCompareAbsoluteValues);
 /** returns true if last line in file is empty or the line starts with the number sign */
-bool testFileForEOFContainsCharacters(std::string sFileName);
+bool testFileForEOFContainsCharacters(const std::string& sFileName);
 void createPi0Vectors(const xAOD::TauJet* xTau, std::vector<TLorentzVector>& vPi0s);
 void correctedPi0Vectors(const xAOD::TauJet* xTau, std::vector<TLorentzVector>& correctedPi0s, TLorentzVector& TauP4);
 /** return charged and neutral daughters of truth tau */

PhysicsAnalysis/TauID/TauAnalysisTools/TauAnalysisTools/TauSelectionCuts.h

 /*
-  Copyright (C) 2002-2023 CERN for the benefit of the ATLAS collaboration
+  Copyright (C) 2002-2024 CERN for the benefit of the ATLAS collaboration
 */
 
 #ifndef TAUANALYSISTOOLS_TAUSELECTIONCUTS_H
@@ -39,7 +39,7 @@ public:
                       asg::AcceptData& accept) = 0;
   TH1F* CreateControlPlot(const char* sName, const char* sTitle, int iBins, double dXLow, double dXUp);
 
-  std::string getName()
+  const std::string& getName()
   {
     return m_sName;
   };