virtio_net: Update driver to use ethtool_sprintf

Update the code to replace instances of snprintf and a pointer update with
just calling ethtool_sprintf.

Also replace the char pointer with a u8 pointer to avoid having to recast
the pointer type.
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: Alexander Duyck <alexanderduyck@fb.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/virtio_net.c

@@ -2138,25 +2138,21 @@ static int virtnet_set_channels(struct net_device *dev,
 static void virtnet_get_strings(struct net_device *dev, u32 stringset, u8 *data)
 {
 	struct virtnet_info *vi = netdev_priv(dev);
-	char *p = (char *)data;
 	unsigned int i, j;
+	u8 *p = data;
 
 	switch (stringset) {
 	case ETH_SS_STATS:
 		for (i = 0; i < vi->curr_queue_pairs; i++) {
-			for (j = 0; j < VIRTNET_RQ_STATS_LEN; j++) {
-				snprintf(p, ETH_GSTRING_LEN, "rx_queue_%u_%s",
-					 i, virtnet_rq_stats_desc[j].desc);
-				p += ETH_GSTRING_LEN;
-			}
+			for (j = 0; j < VIRTNET_RQ_STATS_LEN; j++)
+				ethtool_sprintf(&p, "rx_queue_%u_%s", i,
+						virtnet_rq_stats_desc[j].desc);
 		}
 
 		for (i = 0; i < vi->curr_queue_pairs; i++) {
-			for (j = 0; j < VIRTNET_SQ_STATS_LEN; j++) {
-				snprintf(p, ETH_GSTRING_LEN, "tx_queue_%u_%s",
-					 i, virtnet_sq_stats_desc[j].desc);
-				p += ETH_GSTRING_LEN;
-			}
+			for (j = 0; j < VIRTNET_SQ_STATS_LEN; j++)
+				ethtool_sprintf(&p, "tx_queue_%u_%s", i,
+						virtnet_sq_stats_desc[j].desc);
 		}
 		break;
 	}