merge: don't run post-hook logic on --no-verify
Fix a minor bug introduced in bc40ce4de61 (merge: --no-verify to bypass pre-merge-commit hook, 2019-08-07), when that change made the --no-verify option bypass the "pre-merge-commit" hook it didn't update the corresponding find_hook() (later hook_exists()) condition. As can be seen in the preceding commit in 6098817fd7f (git-merge: honor pre-merge-commit hook, 2019-08-07) the two should go hand in hand. There's no point in invoking discard_cache() here if the hook couldn't have possibly updated the index. It's buggy that we use "hook_exist()" here, and as discussed in the subsequent commit it's subject to obscure race conditions that we're about to fix, but for now this change is a strict improvement that retains any caveats to do with the use of "hooks_exist()" as-is. Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>