merge-base: free() allocated "struct commit **" list
Fix a memory leak in
53eda89b2fe (merge-base: teach "git merge-base"
to drive underlying merge_bases_many(), 2008-07-30) by calling free()
on the "struct commit **" list used by "git merge-base".
This gets e.g. "t6010-merge-base.sh" closer to passing under
SANITIZE=leak, it failed 8 tests before when compiled with that
option, and now fails only 5 tests.
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>