In the queue registry test, start_sem is given twice to let both tasks
start the test. Each task takes start_sem, does some work, gives done_sem,
and goes on to wait for start_sem again.
It may happen that one task can grab start_sem, add queues to the
registry, give done_sem, then grab start_sem again, delete the queues
from the registry, and give done_sem again. At this point, main test
task takes done_sem twice and proceeds to verify that queues have been
added to the registry. But in fact, the first task has already deleted
its queues from the registry, and the second one might not have added
the queues yet. This causes test to fail.
This changes the test to use separate start semaphores for each task,
to avoid the race condition.
8b56345e44