virtio_net: missing sg_init_table

Add missing sg_init_table for sg_set_buf in virtio_net which
induced in defer skb patch.
Reported-by: NThomas Müller <thomas@mathtm.de>
Tested-by: NThomas Müller <thomas@mathtm.de>
Signed-off-by: NShirley Ma <xma@us.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

drivers/net/virtio_net.c

@@ -327,6 +327,7 @@ static int add_recvbuf_small(struct virtnet_info *vi, gfp_t gfp)
 	struct scatterlist sg[2];
 	int err;
 
+	sg_init_table(sg, 2);
 	skb = netdev_alloc_skb_ip_align(vi->dev, MAX_PACKET_LEN);
 	if (unlikely(!skb))
 		return -ENOMEM;
@@ -352,6 +353,7 @@ static int add_recvbuf_big(struct virtnet_info *vi, gfp_t gfp)
 	char *p;
 	int i, err, offset;
 
+	sg_init_table(sg, MAX_SKB_FRAGS + 2);
 	/* page in sg[MAX_SKB_FRAGS + 1] is list tail */
 	for (i = MAX_SKB_FRAGS + 1; i > 1; --i) {
 		first = get_a_page(vi, gfp);