o add a ``done'' flag for crypto operations; this is set when the operation
completes and is intended for callers to check operations that may complete
``prematurely'' because of direct callbacks
o close a race for operations where the crypto driver returns ERESTART: we
need to hold the q lock to insure the blocked state for the driver and any
driver-private state is consistent; otherwise drivers may take an interrupt
and notify the crypto subsystem that it can unblock the driver but operations
will be left queued and never be processed
o close a race in /dev/crypto where operations can complete before the caller
can sleep waiting for the callback: use a per-session mutex and the new done
flag to handle this
o correct crypto_dispatch's handling of operations where the driver returns
ERESTART: the return value must be zero and not ERESTART, otherwise the
caller may free the crypto request despite it being queued for later handling
(this typically results in a later panic)
o change crypto mutex ``names'' so witness printouts and the like are more
meaningful