Cleanup vnd(4) a bit now that it only has one mode of operation and uses standard disk device numbering.
Cleanup vnd(4) a bit now that it only has one mode of operation and
uses standard disk device numbering.

ok deraadt@

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