iso: use -allow-multidot option when calling genisoimage

To properly support syslinux menus we need to provide fonts (specially
when using accents and like) and those files are usually found on
systems using multiple dots on their filenames (e.g iso01.f14.psf) and
then makes sense to support this by default or our users can spent _a
lot_ of time to sort this kind of problem out.

While doing it, the duplicated command line has been removed and code
changed to avoid this duplication making future changes need to touch
just one place.

0 files changed, 0 insertions, 0 deletions