When plugging and unplugging an adapter continuously, it waits for a timeout

When plugging and unplugging an adapter continuously, it waits for a timeout
over and over again.  The problem is that the device has been unplugged,
but the attach handler still issues USB requests via ure_ctl().

The easiest solution is to deactivate the device proactively in
ure_ctl() when we see that error there.

From Christian Ludwig