t/t5*: merge a "grep | sed" pipeline

Signed-off-by: Beat Bolli <dev+git@drbeat.li>
Acked-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

t/t5401-update-hooks.sh

@@ -123,7 +123,7 @@ remote: STDOUT post-update
 remote: STDERR post-update
 EOF
 test_expect_success 'send-pack stderr contains hook messages' '
-	grep ^remote: send.err | sed "s/ *\$//" >actual &&
+	sed -n "/^remote:/s/ *\$//p" send.err >actual &&
 	test_cmp expect actual
 '