EGammaVariableCorrection fix thread safety warnings
Just pass the variable as extra arguement between the method rather than mutating a member.
Should fix one of the issues identified for [!53506 (merged)]
[ 84%] Building CXX object Reconstruction/Jet/JetRec/CMakeFiles/JetRecLib.dir/Root/JetConstituentsRetriever.cxx.o
/var/lib/jenkins/workspace/CI-MERGE-REQUEST-CC7/master/PhysicsAnalysis/ElectronPhotonID/EGammaVariableCorrection/Root/ElectronPhotonVariableCorrectionBase.cxx: In member function 'const StatusCode ElectronPhotonVariableCorrectionBase::setCorrectionParameters(float, float, float) const':
/var/lib/jenkins/workspace/CI-MERGE-REQUEST-CC7/master/PhysicsAnalysis/ElectronPhotonID/EGammaVariableCorrection/Root/ElectronPhotonVariableCorrectionBase.cxx:713:46: warning: Function 'const StatusCode ElectronPhotonVariableCorrectionBase::setCorrectionParameters(float, float, float) const' calling non-const function 'virtual void TF1::SetParameter(Int_t, Double_t)' via member pointer/reference 'ElectronPhotonVariableCorrectionBase::m_correctionFunctionTF1'; may not be thread-safe
713 | m_correctionFunctionTF1->SetParameter(parameter_itr,properties.at(parameter_itr))