debug_smp_processor_id() fixlets

- Account for debug_smp_processor_id()'s own preempt_disable() when
  displaying the preempt_count().

- 80 cols, not 800.

Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>