Simplify ifdefs.  Ensure a MBR-originated fake label will be chosen before the more minimal label that used to get precedence.  Comment some more.
Simplify ifdefs.  Ensure a MBR-originated fake label will be chosen before the
more minimal label that used to get precedence.  Comment some more.

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