Get methods segfaulted when vtkUniformGridAMR::AMRInfo was null.
Get methods segfaulted when vtkUniformGridAMR::AMRInfo was null.

These methods were found by TestSetGet.

Change-Id: I5488647a7b181922ef6059e1799e8d155d010fa8

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