net/virtio: fix unexpected event after reconnect

net/virtio: fix unexpected event after reconnect

Event notification should be disabled after virtqueue initialization and
enabled by calling rte_eth_dev_rx_intr_enable later. When virtio user
device reconnecting to vhost, virtqueue_disable_intr should be called to
disable event notification.

Fixes: 6ebbf4109f35 ("net/virtio-user: fix packed ring server mode")
Cc: stable@dpdk.org
Signed-off-by: Marvin Liu <yong.liu@intel.com>
Acked-by: Xiao Wang <xiao.w.wang@intel.com>
Reviewed-by: Maxime Coquelin <maxime.coquelin@redhat.com>