Fix ahead
Fix ahead

ahead calls to skip to avoid problems with spaces, but it didn't
check the value returned by skip, so in the end of the file it was
not returning EOFTOK, like is desired.

k0gaMSX/scc,8l/scc,k0gaMSX/scc,8l/scc,k0gaMSX/kcc,k0gaMSX/scc,k0gaMSX/kcc,8l/scc