Fix a memory leak in t/helper/test-prio-queue.c, the lack of freeing
the memory with clear_prio_queue() has been there ever since this code
was originally added in b4b594a315 (prio-queue: priority queue of
pointers to structs, 2013-06-06).
By fixing this leak we can cleanly run t0009-prio-queue.sh under
SANITIZE=leak, so annotate it as such with
TEST_PASSES_SANITIZE_LEAK=true.
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>