kernel: fix dummy init thread prio in preempt-only configurations

A thread cannot have a coop priority in this case. It turns out a
priority is not needed when a thread is not inserted in the ready queue,
which is the case with the dummy thread.

The comment was also out-of-date, since it referred to a nanokernel
concept.

Change-Id: Id117501164bd72383d53f3df13030cf95dadc38b
Signed-off-by: Benjamin Walsh <benjamin.walsh@windriver.com>
1 file changed