Remove the refs_read_ref_full() wrapper in favor of migrating various
refs.c API users to the underlying refs_werrres_ref_unsafe() function.
A careful reading of these callers shows that the callers of this
function did not care about "errno", by moving away from the
refs_resolve_ref_unsafe() wrapper we can be sure that nothing relies
on it anymore.
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>