Fix build for vtrViewer code example (match refactor of Far::StencilFactory)
Fix build for vtrViewer code example (match refactor of Far::StencilFactory)

poljere/OpenSubdiv,poljere/OpenSubdiv,poljere/OpenSubdiv,shengfuintel/OpenSubdiv,lookup1980/OpenSubdiv,takahito-tejima/OpenSubdiv,anshuarya/OpenSubdiv,lookup1980/OpenSubdiv,jcowles/OpenSubdiv,nyotis/OpenSubdiv,c64kernal/OpenSubdiv,c64kernal/OpenSubdiv,takahito-tejima/OpenSubdiv,anshuarya/OpenSubdiv,xldeveloper/OpenSubdiv,shengfuintel/OpenSubdiv,c64kernal/OpenSubdiv,nyotis/OpenSubdiv,xldeveloper/OpenSubdiv,xldeveloper/OpenSubdiv,shengfuintel/OpenSubdiv,lookup1980/OpenSubdiv,takahito-tejima/OpenSubdiv,jcowles/OpenSubdiv,nyotis/OpenSubdiv,jcowles/OpenSubdiv,anshuarya/OpenSubdiv