sched: Fix task-priority when using SCHED_RESET_ON_FORK

If a call to setscheduler tries to assign a task both RT priority
and SCHED_RESET_ON_FORK, the scheduler currently sets the
priority incorrectly, resulting in not only reporting the priority
incorrectly, but also in scheduling the task using the fair scheduler
(because the check for RT sees extra bit for RESET_ON_FORK).

Bug: 27705114
Change-Id: I2eaa137a759cd39e1e98f8d5e1caea046877330d
Signed-off-by: Vaisakh Murali <mvaisakh@statixos.com>