net/virtio-user: fix status management

net/virtio-user: fix status management

Apart from the virtio status, there should be also a network related
status for link status management, current implementation mixes up these
two statuses.

One issue caused by this mixup is when virtio-user running in server mode
and vhost as a client connects to it, a RARP packet will be generated by
virtio-user due to VIRTIO_NET_S_ANNOUNCE bit is detected in the "status"
in interrupt handler.

VIRTIO_NET_S_LINK_UP and VIRTIO_NET_S_ANNOUNCE should be managed by a
separated field. This patch adds a "net_status" field for this purpose.

Fixes: e9efa4d93821 ("net/virtio-user: add new virtual PCI driver")
Cc: stable@dpdk.org
Signed-off-by: Adrian Moreno <amorenoz@redhat.com>
Signed-off-by: Xiao Wang <xiao.w.wang@intel.com>
Reviewed-by: Chenbo Xia <chenbo.xia@intel.com>
Reviewed-by: Maxime Coquelin <maxime.coquelin@redhat.com>