fixup! backend: Dedup some code for temporary auth subjects
See https://bugs.freedesktop.org/show_bug.cgi?id=23867 which turned up from `git annotate` here. I was reading this code and noticed it was duplicated.
See https://bugs.freedesktop.org/show_bug.cgi?id=23867 which turned up from `git annotate` here. I was reading this code and noticed it was duplicated.