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>