[Drbd-dev] Barrier assert failures with latest 8.0 sources

[Graham, Simon]

> I think the fixes are:
> 
> a. Don't do queue_barrier if the connection state is <Connected
> b. Make sure the flag is clear in drbd_connect
> c. Modify w_send_barrier to decrement the ap count if it decides to
not
>    send a barrier (e.g. if the connection is lost between the time the
>    work item is queued and the time it runs).
> 

Scratch item c) -- tl_clear already does this...
/simgr