net: usb: remove duplicate assignment

netdev_alloc_skb() has assigned ssi->netdev to skb->dev if successed,
no need to repeat assignment.
Signed-off-by: Wang Qing <wangqing@vivo.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/usb/qmi_wwan.c

@@ -190,7 +190,6 @@ static int qmimux_rx_fixup(struct usbnet *dev, struct sk_buff *skb)
 		skbn = netdev_alloc_skb(net, pkt_len + LL_MAX_HEADER);
 		if (!skbn)
 			return 0;
-		skbn->dev = net;
 
 		switch (skb->data[offset + qmimux_hdr_sz] & 0xf0) {
 		case 0x40: