Eliminated unneeded null checks before using delete/free

Charts/Core/vtkPlotPoints.cxx

Common/Core/vtkAbstractArray.cxx

Common/Core/vtkBitArray.cxx

Common/Core/vtkDataArrayTemplate.txx

Common/Core/vtkDebugLeaks.cxx

Common/Core/vtkFileOutputWindow.cxx

Common/Core/vtkMappedDataArray.txx

Common/Core/vtkStringArray.cxx

Common/Core/vtkVariantArray.cxx

Common/DataModel/vtkDataSetAttributes.cxx

Common/DataModel/vtkEdgeTable.cxx

Common/DataModel/vtkExtractStructuredGridHelper.cxx

Common/DataModel/vtkGenericAdaptorCell.cxx

Common/DataModel/vtkGenericCellTessellator.cxx

Common/DataModel/vtkSimpleCellTessellator.cxx

Common/DataModel/vtkTreeBFSIterator.cxx

Common/DataModel/vtkTreeDFSIterator.cxx

Common/ExecutionModel/vtkAlgorithm.cxx

Common/ExecutionModel/vtkExtentTranslator.cxx

Examples/GUI/Win32/SimpleCxx/Win32Cone.cxx