Does a minor reshuffling of logic to ensure that the idle task
continues to busy wait even if _workload_loop() unexpectedly
returns. Also enhances associated comments to make the operation
of the idle task a bit clearer.
Change-Id: Ie6fd3fde0b088770815b1946415d213ee0e54a4b
Signed-off-by: Allan Stephens <allan.stephens@windriver.com>