Fixed crash in PokeMatrix(NULL) if not called before with valid data.
Fixed crash in PokeMatrix(NULL) if not called before with valid data.

Change-Id: I48d0a7988e5035dac6508687015fcc9da58fe293

sumedhasingla/VTK,demarle/VTK,gram526/VTK,sankhesh/VTK,keithroe/vtkoptix,SimVascular/VTK,mspark93/VTK,sankhesh/VTK,keithroe/vtkoptix,sumedhasingla/VTK,SimVascular/VTK,keithroe/vtkoptix,mspark93/VTK,msmolens/VTK,candy7393/VTK,gram526/VTK,msmolens/VTK,candy7393/VTK,mspark93/VTK,jmerkow/VTK,sankhesh/VTK,sankhesh/VTK,candy7393/VTK,sumedhasingla/VTK,sumedhasingla/VTK,jmerkow/VTK,msmolens/VTK,msmolens/VTK,gram526/VTK,SimVascular/VTK,demarle/VTK,sankhesh/VTK,SimVascular/VTK,sankhesh/VTK,jmerkow/VTK,candy7393/VTK,demarle/VTK,jmerkow/VTK,SimVascular/VTK,msmolens/VTK,sumedhasingla/VTK,msmolens/VTK,candy7393/VTK,gram526/VTK,candy7393/VTK,mspark93/VTK,msmolens/VTK,jmerkow/VTK,jmerkow/VTK,mspark93/VTK,keithroe/vtkoptix,gram526/VTK,keithroe/vtkoptix,mspark93/VTK,demarle/VTK,candy7393/VTK,sumedhasingla/VTK,SimVascular/VTK,demarle/VTK,SimVascular/VTK,gram526/VTK,demarle/VTK,gram526/VTK,sankhesh/VTK,jmerkow/VTK,keithroe/vtkoptix,mspark93/VTK,sankhesh/VTK,candy7393/VTK,sumedhasingla/VTK,mspark93/VTK,keithroe/vtkoptix,sumedhasingla/VTK,demarle/VTK,gram526/VTK,demarle/VTK,msmolens/VTK,jmerkow/VTK,SimVascular/VTK,keithroe/vtkoptix