STYLE: Fix typo in GetFilenameLastExtension docs
STYLE: Fix typo in GetFilenameLastExtension docs

See issue #7797.

keithroe/vtkoptix,demarle/VTK,arnaudgelas/VTK,johnkit/vtk-dev,spthaolt/VTK,jmerkow/VTK,cjh1/VTK,collects/VTK,gram526/VTK,sumedhasingla/VTK,gram526/VTK,berendkleinhaneveld/VTK,daviddoria/PointGraphsPhase1,SimVascular/VTK,sumedhasingla/VTK,johnkit/vtk-dev,spthaolt/VTK,gram526/VTK,aashish24/VTK-old,demarle/VTK,Wuteyan/VTK,msmolens/VTK,spthaolt/VTK,aashish24/VTK-old,daviddoria/PointGraphsPhase1,hendradarwin/VTK,gram526/VTK,ashray/VTK-EVM,johnkit/vtk-dev,cjh1/VTK,SimVascular/VTK,msmolens/VTK,jmerkow/VTK,arnaudgelas/VTK,collects/VTK,cjh1/VTK,Wuteyan/VTK,mspark93/VTK,jmerkow/VTK,mspark93/VTK,arnaudgelas/VTK,naucoin/VTKSlicerWidgets,jeffbaumes/jeffbaumes-vtk,biddisco/VTK,ashray/VTK-EVM,candy7393/VTK,Wuteyan/VTK,johnkit/vtk-dev,ashray/VTK-EVM,ashray/VTK-EVM,spthaolt/VTK,hendradarwin/VTK,jeffbaumes/jeffbaumes-vtk,biddisco/VTK,aashish24/VTK-old,msmolens/VTK,naucoin/VTKSlicerWidgets,mspark93/VTK,cjh1/VTK,sankhesh/VTK,keithroe/vtkoptix,biddisco/VTK,cjh1/VTK,mspark93/VTK,naucoin/VTKSlicerWidgets,berendkleinhaneveld/VTK,gram526/VTK,sumedhasingla/VTK,keithroe/vtkoptix,ashray/VTK-EVM,SimVascular/VTK,spthaolt/VTK,collects/VTK,candy7393/VTK,msmolens/VTK,mspark93/VTK,keithroe/vtkoptix,hendradarwin/VTK,Wuteyan/VTK,jmerkow/VTK,candy7393/VTK,sankhesh/VTK,jmerkow/VTK,sankhesh/VTK,collects/VTK,collects/VTK,SimVascular/VTK,naucoin/VTKSlicerWidgets,johnkit/vtk-dev,keithroe/vtkoptix,jeffbaumes/jeffbaumes-vtk,SimVascular/VTK,sumedhasingla/VTK,ashray/VTK-EVM,candy7393/VTK,aashish24/VTK-old,demarle/VTK,jeffbaumes/jeffbaumes-vtk,naucoin/VTKSlicerWidgets,keithroe/vtkoptix,candy7393/VTK,jeffbaumes/jeffbaumes-vtk,hendradarwin/VTK,hendradarwin/VTK,mspark93/VTK,SimVascular/VTK,SimVascular/VTK,ashray/VTK-EVM,candy7393/VTK,sankhesh/VTK,gram526/VTK,cjh1/VTK,msmolens/VTK,ashray/VTK-EVM,jmerkow/VTK,sankhesh/VTK,candy7393/VTK,Wuteyan/VTK,jeffbaumes/jeffbaumes-vtk,msmolens/VTK,aashish24/VTK-old,arnaudgelas/VTK,berendkleinhaneveld/VTK,demarle/VTK,collects/VTK,johnkit/vtk-dev,candy7393/VTK,arnaudgelas/VTK,biddisco/VTK,demarle/VTK,demarle/VTK,sankhesh/VTK,sumedhasingla/VTK,msmolens/VTK,keithroe/vtkoptix,biddisco/VTK,naucoin/VTKSlicerWidgets,gram526/VTK,spthaolt/VTK,daviddoria/PointGraphsPhase1,gram526/VTK,berendkleinhaneveld/VTK,berendkleinhaneveld/VTK,sankhesh/VTK,mspark93/VTK,jmerkow/VTK,berendkleinhaneveld/VTK,arnaudgelas/VTK,sumedhasingla/VTK,daviddoria/PointGraphsPhase1,spthaolt/VTK,jmerkow/VTK,msmolens/VTK,daviddoria/PointGraphsPhase1,sumedhasingla/VTK,sumedhasingla/VTK,keithroe/vtkoptix,daviddoria/PointGraphsPhase1,demarle/VTK,mspark93/VTK,Wuteyan/VTK,demarle/VTK,aashish24/VTK-old,hendradarwin/VTK,hendradarwin/VTK,Wuteyan/VTK,biddisco/VTK,biddisco/VTK,berendkleinhaneveld/VTK,SimVascular/VTK,johnkit/vtk-dev,sankhesh/VTK