Fix bug in with GetPlotType() in vtkScatterPlotMatrix
Fix bug in with GetPlotType() in vtkScatterPlotMatrix

This fixes a bug which resulted in the chart backgrounds being
set incorrectly due to GetPlotType() being called with the wrong
position argument in the SetActivePlot().

Change-Id: Ifee38c0126dfbf982519f0a7d696b008d83ad6a3

spthaolt/VTK,spthaolt/VTK,johnkit/vtk-dev,gram526/VTK,berendkleinhaneveld/VTK,collects/VTK,johnkit/vtk-dev,gram526/VTK,cjh1/VTK,johnkit/vtk-dev,demarle/VTK,msmolens/VTK,jmerkow/VTK,ashray/VTK-EVM,sankhesh/VTK,msmolens/VTK,biddisco/VTK,gram526/VTK,candy7393/VTK,msmolens/VTK,keithroe/vtkoptix,candy7393/VTK,sumedhasingla/VTK,collects/VTK,mspark93/VTK,mspark93/VTK,SimVascular/VTK,candy7393/VTK,biddisco/VTK,aashish24/VTK-old,hendradarwin/VTK,biddisco/VTK,msmolens/VTK,cjh1/VTK,cjh1/VTK,aashish24/VTK-old,hendradarwin/VTK,berendkleinhaneveld/VTK,msmolens/VTK,biddisco/VTK,sankhesh/VTK,johnkit/vtk-dev,gram526/VTK,jmerkow/VTK,SimVascular/VTK,demarle/VTK,candy7393/VTK,mspark93/VTK,aashish24/VTK-old,SimVascular/VTK,msmolens/VTK,collects/VTK,SimVascular/VTK,spthaolt/VTK,johnkit/vtk-dev,aashish24/VTK-old,gram526/VTK,sumedhasingla/VTK,jmerkow/VTK,jmerkow/VTK,cjh1/VTK,biddisco/VTK,keithroe/vtkoptix,sankhesh/VTK,berendkleinhaneveld/VTK,berendkleinhaneveld/VTK,demarle/VTK,aashish24/VTK-old,hendradarwin/VTK,berendkleinhaneveld/VTK,biddisco/VTK,demarle/VTK,ashray/VTK-EVM,collects/VTK,jmerkow/VTK,candy7393/VTK,spthaolt/VTK,mspark93/VTK,johnkit/vtk-dev,demarle/VTK,ashray/VTK-EVM,sumedhasingla/VTK,mspark93/VTK,hendradarwin/VTK,aashish24/VTK-old,johnkit/vtk-dev,ashray/VTK-EVM,msmolens/VTK,sumedhasingla/VTK,berendkleinhaneveld/VTK,biddisco/VTK,keithroe/vtkoptix,candy7393/VTK,sumedhasingla/VTK,SimVascular/VTK,SimVascular/VTK,demarle/VTK,jmerkow/VTK,ashray/VTK-EVM,msmolens/VTK,sankhesh/VTK,jmerkow/VTK,sankhesh/VTK,mspark93/VTK,gram526/VTK,cjh1/VTK,demarle/VTK,mspark93/VTK,candy7393/VTK,sumedhasingla/VTK,spthaolt/VTK,berendkleinhaneveld/VTK,keithroe/vtkoptix,keithroe/vtkoptix,sankhesh/VTK,collects/VTK,sumedhasingla/VTK,candy7393/VTK,collects/VTK,hendradarwin/VTK,sankhesh/VTK,keithroe/vtkoptix,jmerkow/VTK,ashray/VTK-EVM,gram526/VTK,spthaolt/VTK,SimVascular/VTK,demarle/VTK,hendradarwin/VTK,keithroe/vtkoptix,ashray/VTK-EVM,ashray/VTK-EVM,keithroe/vtkoptix,sumedhasingla/VTK,cjh1/VTK,hendradarwin/VTK,SimVascular/VTK,sankhesh/VTK,gram526/VTK,spthaolt/VTK,mspark93/VTK