Catch failures from t5540-http-push

Catch failures from t5540-http-push

git http-push doesn't handle packed-refs, and now the new builtin-clone
created packed refs, the http-push test fails.

Mark the current failure as such, and also catch third test's failure
that went unreported because git push doesn't return an error code when
it says:
 No refs in common and none specified; doing nothing.
Which it does when http-push can't get a list of refs recursively from
$URL/refs/.

Signed-off-by: Mike Hommey <mh@glandium.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>