git-send-email: Respect core.hooksPath setting

get-send-email currently makes the assumption that the
'sendemail-validate' hook exists inside of the repository.

Since the introduction of 'core.hooksPath' configuration option in
867ad08a26 (hooks: allow customizing where the hook directory is,
2016-05-04), this is no longer true.

Instead of assuming a hardcoded repo relative path, query
git for the actual path of the hooks directory.

Signed-off-by: Robert Foss <robert.foss@linaro.org>
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

git-send-email.perl

@@ -1942,7 +1942,7 @@ sub validate_patch {
 	my ($fn, $xfer_encoding) = @_;
 
 	if ($repo) {
-		my $validate_hook = catfile(catdir($repo->repo_path(), 'hooks'),
+		my $validate_hook = catfile($repo->hooks_path(),
 					    'sendemail-validate');
 		my $hook_error;
 		if (-x $validate_hook) {