lockdep: Comment all warnings

Andrew requested I comment all the lockdep WARN()s to help other people
figure out wth is wrong..

Requested-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1315301493.3191.9.camel@twins


Signed-off-by: Ingo Molnar <mingo@elte.hu>