netdevice: safe convert to netdev_priv() #part-3

We have some reasons to kill netdev->priv:
1. netdev->priv is equal to netdev_priv().
2. netdev_priv() wraps the calculation of netdev->priv's offset, obviously
   netdev_priv() is more flexible than netdev->priv.
But we cann't kill netdev->priv, because so many drivers reference to it
directly.

This patch is a safe convert for netdev->priv to netdev_priv(netdev).
Since all of the netdev->priv is only for read.
But it is too big to be sent in one mail.
I split it to 4 parts and make every part smaller than 100,000 bytes,
which is max size allowed by vger.

Signed-off-by: Wang Chen <wangchen@cn.fujitsu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index 68f908a..ede0a80 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -125,7 +125,8 @@
 		unsigned int i;
 
 		for (i = 0; i < skb_shinfo(skb)->nr_frags; i++)
-			give_a_page(dev->priv, skb_shinfo(skb)->frags[i].page);
+			give_a_page(netdev_priv(dev),
+				    skb_shinfo(skb)->frags[i].page);
 		skb->data_len = 0;
 		skb_shinfo(skb)->nr_frags = 0;
 	}