vDPA: check VIRTIO_NET_F_RSS for max_virtqueue_paris's presence

virtio 1.2 spec says:
max_virtqueue_pairs only exists if VIRTIO_NET_F_MQ or
VIRTIO_NET_F_RSS is set.

So when reporint MQ to userspace, it should check both
VIRTIO_NET_F_MQ and VIRTIO_NET_F_RSS.

unused parameter struct vdpa_device *vdev is removed

Signed-off-by: Zhu Lingshan <lingshan.zhu@intel.com>
Acked-by: Jason Wang <jasowang@redhat.com>
Message-Id: <20220929014555.112323-4-lingshan.zhu@intel.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

drivers/vdpa/vdpa.c

@@ -804,13 +804,13 @@ static int vdpa_nl_cmd_dev_get_dumpit(struct sk_buff *msg, struct netlink_callba
 	return msg->len;
 }
 
-static int vdpa_dev_net_mq_config_fill(struct vdpa_device *vdev,
-				       struct sk_buff *msg, u64 features,
+static int vdpa_dev_net_mq_config_fill(struct sk_buff *msg, u64 features,
 				       const struct virtio_net_config *config)
 {
 	u16 val_u16;
 
-	if ((features & BIT_ULL(VIRTIO_NET_F_MQ)) == 0)
+	if ((features & BIT_ULL(VIRTIO_NET_F_MQ)) == 0 &&
+	    (features & BIT_ULL(VIRTIO_NET_F_RSS)) == 0)
 		return 0;
 
 	val_u16 = le16_to_cpu(config->max_virtqueue_pairs);