vtkfreetype: Cast ulong->int to avoid comparison warning
vtkfreetype: Cast ulong->int to avoid comparison warning

Avoid warning

 src/base/ftbitmap.c:421: warning: comparison between signed
 and unsigned integer expressions [-Wsign-compare]

Change-Id: I67e4c346f078e83f837b7bd8303be00cf845bfe5

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