patch 3aa416b0 in mainline.


 It is possible for the current->curr_chain_key to become inconsistent with the
 current index if the chain fails to validate.  The end result is that future
 lock_acquire() operations may inadvertently fail to find a hit in the cache
 resulting in a new node being added to the graph for every acquire.
Signed-off-by: Gregory Haskins <ghaskins@novell.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Cc: Chuck Ebbert <cebbert@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>