this was only used in one place, and that place has been rewritten to
use a temporary file instead. keeping this around is not very helpful
at this time, and in any case we'd be better off rewriting subprocess
handling in rust where we not only have a much safer library for such
things but also async frameworks necessary for this easily available.
Change-Id: I6f8641b756857c84ae2602cdf41f74ee7a1fda02