Set mp_nbusses such that the newly added bounds checks on i386 and amd64 don't fail unconditionally.
Set mp_nbusses such that the newly added bounds checks on i386 and amd64
don't fail unconditionally.

orumin/openbsd-efivars,orumin/openbsd-efivars,orumin/openbsd-efivars,orumin/openbsd-efivars