In order to reset the guest agent, we send CLOSED & OPENED events.

They are correctly received by the guest kernel. However, they might not
be noticed by the guest agent process, as the IO task (poll() for
example) might be wake up after both CLOSED & OPENED have been
processed.

Wait until the guest agent is disconnected to re-open our side.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <20220912102455.111765-6-marcandre.lureau@redhat.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>