The expected SHA-1 digests are always available in variables. Use
them instead of hardcoding.
That was introduced in a742f2a (t4205 (log-pretty-formats): don't
hardcode SHA-1 in expected outputs, 2013-06-26) but unfortunately was
not followed in 5e1361c (log: properly handle decorations with chained
tags, 2013-12-17)
Signed-off-by: Alexey Shumkin <Alex.Crezoff@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>