sched: Move TASK_STATE_TO_CHAR_STR near the TASK_state bits

So that we don't keep forgetting about it.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <20091217121829.815779372@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>