Fix for polyhedron cells.
Fix for polyhedron cells.

This happens for datasets containing a mixture of cell types.  The
vtkIdList was not reset consistently between polyhedron cells and other
cell types.

Change-Id: I2ace508eff3515ac2b6173250d8e2d338e4ba3de

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