Store a reference to the server in the SpiceCharDeviceState struct and
use that rather than the global 'reds' variable
Acked-by: Frediano Ziglio <fziglio@redhat.com>
Since this is public API, we can't easily change the signature of the
function to take a RedsState argument, so instead we apply a hack and
store the reds argument inside the device state struct when the
interface is added, and retrieve it for use later when it is removed.
Acked-by: Pavel Grunt <pgrunt@redhat.com>