test-lib tests: get rid of copy/pasted mock test code
Now that we've split up the write_sub_test_lib_test*() and
run_sub_test_lib_test*() functions let's fix those tests in
t0000-basic.sh that were verbosely copy/pasting earlier tests.
That we caught all of them was asserted with a follow-up change that's
not part of this series[1], we might add such a duplication check at
some later time, but for now let's just one-off remove the duplicate
boilerplate.
1. https://lore.kernel.org/git/patch-v3-6.9-
bc79b29f3c-20210805T103237Z-avarab@gmail.com/
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>