ui/console: free more QemuConsole resources

This code path is probably not executed at this point, since console
aren't being released.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Message-Id: <20230830093843.3531473-28-marcandre.lureau@redhat.com>