Add a function that can be used through libdlm by a system daemon to cancel
another process's deadlocked lock.  A completion ast with EDEADLK is returned
to the process waiting for the lock.
Signed-off-by: NDavid Teigland <teigland@redhat.com>
Signed-off-by: NSteven Whitehouse <swhiteho@redhat.com>