Also use TEST_ASSERT_EQUAL to get better debugging
Debugging intermittent UT failures on S2 release config
In the old version, the 300ms delay in between the two kinds of test
was supposed to keep the tasks in lockstep so it didn't matter that
global_sp was protected by two muxes.
However it seems like sometimes they could get out of sync -
I think because of a race in the sleep_until test. If the
second counter ticks over at that exact moment sleeping starts,
then the task doesn't sleep and will immediately keep running
for the next iteration, possibly racing the other tasks.
