Developers use preempt_enable_no_resched() in places where the code
calls schedule() immediately which is correct. But there are places
where preempt_enable_no_resched() is not followed by schedule().

Add debug infrastructre to find the offending code. The identified
correct users are converted to use __preempt_enable_no_resched().

For the ever repeating "preempt_enable_no_resched(); schedule();"
sequences a onvenience macro preempt_enable_and_schedule() is
introduced.

Based on a previous patch from Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>