Fix the listing of `initfs:` directories
Created by: xTibor
There was a bug at the initfs generation which made the listing of the contents of the initfs:subdirectories impossible from the command line.
The subdirectory listing data had the full paths of the files (like bin/ahcid\nbin/bgad\n...) when it should just only be the names of the files (ahcid\nbgad\n...)
