sched: Fix broken assertion

sched: Fix broken assertion

commit 077614ee1e93245a3b9a4e1213659405dbeb0ba6 upstream

There's a preemption race in the set_task_cpu() debug check in
that when we get preempted after setting task->state we'd still
be on the rq proper, but fail the test.

Check for preempted tasks, since those are always on the RQ.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <20091217121830.137155561@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Mike Galbraith <efault@gmx.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>