virtio/vhost-vsock: don't double close vhostfd, remove redundant cleanup

In case of an error during initialization in vhost_dev_init, vhostfd is
closed in vhost_dev_cleanup. Remove close from err_virtio as it's both
redundant and causes a double close on vhostfd.

Signed-off-by: Daniil Tatianin <d-tatianin@yandex-team.ru>
Message-Id: <20211129125204.1108088-1-d-tatianin@yandex-team.ru>
Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>