With the context rework stuff we can actually end up freeing an event
before it gets attached to a context.
Reported-by: NCyrill Gorcunov <gorcunov@gmail.com>
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <new-submission>
Signed-off-by: NIngo Molnar <mingo@elte.hu>