tests: Use skip_all=* to skip tests

tests: Use skip_all=* to skip tests

Change tests to skip with skip_all=* + test_done instead of using say
+ test_done.

This is a follow-up to "tests: Skip tests in a way that makes sense
under TAP" (fadb5156e4). I missed these cases when prepearing that
patch, hopefully this is all of them.

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