When selecting brand based on old Elf branding, prefer the brand which
interpreter exactly matches the one requested by the activated image.

This change applies r295277, which did the same for note branding, to
the old brand selection, with the same reasoning of fixing compat32
interpreter substitution.

PR: 211837
Reported by: kenji@kens.fm
Sponsored by: The FreeBSD Foundation
MFC after: 1 week