fix direct references to scheme_null in cmdline.inc (which break the Windows build)
fix direct references to scheme_null in cmdline.inc (which break the Windows build)

svn: r8110

mafagafogigante/racket,mafagafogigante/racket,mafagafogigante/racket,mafagafogigante/racket,mafagafogigante/racket,mafagafogigante/racket,mafagafogigante/racket,mafagafogigante/racket,mafagafogigante/racket