t5704: fix nonportable sed/grep usages

OS X's sed and grep would complain with (respectively)

  sed: 1: "/^-/{p;q}": extra characters at the end of q command
  grep: Regular expression too big

For sed, use an explicit ; to terminate the q command.

For grep, spell the "40 hex digits" explicitly in the regex, which
should be safe as other tests already use this and we haven't got
breakage reports on OS X about them.

Signed-off-by: Thomas Rast <trast@inf.ethz.ch>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

t/t5704-bundle.sh

@@ -54,8 +54,8 @@ test_expect_success 'ridiculously long subject in boundary' '
 	git bundle list-heads long-subject-bundle.bdl >heads &&
 	test -s heads &&
 	git fetch long-subject-bundle.bdl &&
-	sed -n "/^-/{p;q}" long-subject-bundle.bdl >boundary &&
-	grep "^-$_x40 " boundary
+	sed -n "/^-/{p;q;}" long-subject-bundle.bdl >boundary &&
+	grep "^-[0-9a-f]\\{40\\} " boundary
 '
 
 test_done