eflowRec: Fix clang15 warnings
/build/atnight/localbuilds/nightlies/Athena/master/athena/Reconstruction/eflowRec/src/PFLCCalibTool.cxx:96:12: warning: variable 'cellIndex' set but not used [-Wunused-but-set-variable]
for (int cellIndex = 0; cellIter != theCluster->cell_end(); cellIter++) {
^bonus also fix these from clang-tidy (this is separate from the clang warnings above)
Reconstruction/eflowRec/src/PFNeutralFlowElementCreatorAlgorithm.cxx:86:32: warning: unnecessary temporary object created while calling emplace_back [modernize-use-emplace]
theClusters.emplace_back(ElementLink<xAOD::IParticleContainer>(theSisterClusterLink));
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ~
Reconstruction/eflowRec/src/PFNeutralFlowElementCreatorAlgorithm.cxx:89:32: warning: unnecessary temporary object created while calling emplace_back [modernize-use-emplace]
theClusters.emplace_back(ElementLink<xAOD::IParticleContainer>(theOriginalClusterLink));
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ~