lockdep: Be nice about building from userspace

Lockdep is an awesome piece of code which detects locking issues
which are relevant both to userspace and kernelspace. We can
easily make lockdep work in userspace since there is really no
kernel spacific magic going on in the code.

All we need is to wrap two functions which are used by lockdep
and are very kernel specific.

Doing that will allow tools located in tools/ to easily utilize
lockdep's code for their own use.

Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Cc: penberg@kernel.org
Cc: torvalds@linux-foundation.org
Link: http://lkml.kernel.org/r/1352753446-24109-1-git-send-email-sasha.levin@oracle.com


Signed-off-by: Ingo Molnar <mingo@kernel.org>