XMLReader: Prevent streams from being closed when they don't exist.
XMLReader: Prevent streams from being closed when they don't exist.

Change-Id: If841a1ad30528499f592e7e6bfc09d146835ab51

gram526/VTK,msmolens/VTK,mspark93/VTK,candy7393/VTK,sumedhasingla/VTK,keithroe/vtkoptix,msmolens/VTK,candy7393/VTK,sankhesh/VTK,gram526/VTK,mspark93/VTK,keithroe/vtkoptix,msmolens/VTK,johnkit/vtk-dev,sankhesh/VTK,keithroe/vtkoptix,jmerkow/VTK,gram526/VTK,demarle/VTK,gram526/VTK,SimVascular/VTK,demarle/VTK,ashray/VTK-EVM,demarle/VTK,msmolens/VTK,gram526/VTK,johnkit/vtk-dev,hendradarwin/VTK,sumedhasingla/VTK,SimVascular/VTK,keithroe/vtkoptix,keithroe/vtkoptix,candy7393/VTK,jmerkow/VTK,hendradarwin/VTK,SimVascular/VTK,sankhesh/VTK,johnkit/vtk-dev,johnkit/vtk-dev,mspark93/VTK,ashray/VTK-EVM,sankhesh/VTK,johnkit/vtk-dev,jmerkow/VTK,sankhesh/VTK,ashray/VTK-EVM,jmerkow/VTK,mspark93/VTK,candy7393/VTK,SimVascular/VTK,hendradarwin/VTK,sumedhasingla/VTK,jmerkow/VTK,sankhesh/VTK,ashray/VTK-EVM,demarle/VTK,gram526/VTK,sumedhasingla/VTK,ashray/VTK-EVM,keithroe/vtkoptix,gram526/VTK,ashray/VTK-EVM,SimVascular/VTK,johnkit/vtk-dev,sankhesh/VTK,keithroe/vtkoptix,candy7393/VTK,mspark93/VTK,mspark93/VTK,demarle/VTK,SimVascular/VTK,msmolens/VTK,msmolens/VTK,jmerkow/VTK,SimVascular/VTK,candy7393/VTK,ashray/VTK-EVM,jmerkow/VTK,hendradarwin/VTK,keithroe/vtkoptix,candy7393/VTK,hendradarwin/VTK,demarle/VTK,gram526/VTK,sankhesh/VTK,mspark93/VTK,msmolens/VTK,sumedhasingla/VTK,demarle/VTK,sumedhasingla/VTK,ashray/VTK-EVM,hendradarwin/VTK,johnkit/vtk-dev,sumedhasingla/VTK,sumedhasingla/VTK,candy7393/VTK,mspark93/VTK,demarle/VTK,msmolens/VTK,hendradarwin/VTK,jmerkow/VTK,SimVascular/VTK