Fixed cppcheck issues

src/colvar/RDC.cpp

src/crystallization/Steinhardt.cpp

src/mapping/SpathVessel.cpp

src/multicolvar/Sprint.cpp

src/reference/PointWiseMapping.cpp

src/reference/ReferenceAtoms.cpp

src/reference/ReferenceConfiguration.cpp

src/secondarystructure/SecondaryStructureRMSD.cpp

src/tools/BiasRepresentation.cpp

src/tools/DynamicList.h

src/tools/LinkCells.cpp

src/tools/OFile.cpp

src/tools/SwitchingFunction.cpp

src/vesselbase/ActionWithInputVessel.h

src/vesselbase/BridgeVessel.cpp

src/vesselbase/FunctionVessel.cpp

src/vesselbase/StoreDataVessel.cpp