Force calling BlockRingPoll as DPC may not run.

Signed-off-by: Owen Smith <owen.smith@citrix.com>
Cleanup PreparedReqs before closing the ring

To unprepare reqs, the granter is required, which can only operate
when the frontend is connected.

Signed-off-by: Owen Smith <owen.smith@citrix.com>
Add extra state to frontend transition to allow reset to cleanup
requests after CLOSED transition but before disconnecting granter

Signed-off-by: Owen Smith <owen.smith@citrix.com>
Merge pull request #34 from OwenSmith/fix-reset

Fix reset

Approved-By: Ben.Chalmers@citrix.com