Fixed clang analyzer warning about reading uninitialized memory.
Fixed clang analyzer warning about reading uninitialized memory.

If 'numDeleted' is not 2 nor 1, 'tri' was used uninitialized; call vtkErrorMacro instead.

Change-Id: Ia0e508184a37e07f3186e192a166d1f38c79cbdb

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