Comment 4 for bug 428958

lock0lock.c:lock_rec_create() had a problem when calling lock_cancel_waiting_and_release().
The lock to cancel was c_lock, which is the the lock that conflicts with BF applier. However c_lock itself
is not waiting. The trx holding c_lock is waiting for some other lock and the fix is to cancel that lock wait
.i.e. c_lock->trx->wait_lock

We assert on the fact that wait_lock remains in effect from lock_rec_other_has_conflicting() until here.