git-send-email: replace "map" in void context with "for"

While using "map" instead of "for" or "map" instead of "grep" and
vice-versa makes for interesting trivia questions when interviewing
Perl programmers, it doesn't make for very readable code. Let's
refactor this loop initially added in 8fd5bb7f44 (git send-email: add
--annotate option, 2008-11-11) to be a for-loop instead.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

git-send-email.perl

@@ -217,12 +217,12 @@ sub do_edit {
 		$editor = Git::command_oneline('var', 'GIT_EDITOR');
 	}
 	if (defined($multiedit) && !$multiedit) {
-		map {
+		for (@_) {
 			system('sh', '-c', $editor.' "$@"', $editor, $_);
 			if (($? & 127) || ($? >> 8)) {
 				die(__("the editor exited uncleanly, aborting everything"));
 			}
-		} @_;
+		}
 	} else {
 		system('sh', '-c', $editor.' "$@"', $editor, @_);
 		if (($? & 127) || ($? >> 8)) {