[PATCH] debug: workqueue locking sanity

Workqueue functions should not leak locks, assert so, printing the
last function ran.

Use macros in lockdep.h to avoid include dependency pains.

[akpm@osdl.org: build fix]
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>