[syslinux] isohybrid --uefi - resulting EF00 partition too small

[Mattias Schlenker]

Argh. I am a bit tired, sorry. Of course. 51 % 32 =19. Yes, it would be helpful if xorriso (and every other ISO creator) gracefully failed for too large el torito images. I was not aware oft this limit. 

Regards, Mattias