ppp: use ndo_siocdevprivate

ppp has a custom statistics interface using SIOCDEVPRIVATE
ioctl commands that works correctly in compat mode.

Convert it to use ndo_siocdevprivate as a cleanup.

Cc: Paul Mackerras <paulus@samba.org>
Cc: linux-ppp@vger.kernel.org
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ppp/ppp_generic.c

@@ -1452,11 +1452,11 @@ ppp_start_xmit(struct sk_buff *skb, struct net_device *dev)
 }
 
 static int
-ppp_net_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
+ppp_net_siocdevprivate(struct net_device *dev, struct ifreq *ifr,
+		       void __user *addr, int cmd)
 {
 	struct ppp *ppp = netdev_priv(dev);
 	int err = -EFAULT;
-	void __user *addr = (void __user *) ifr->ifr_ifru.ifru_data;
 	struct ppp_stats stats;
 	struct ppp_comp_stats cstats;
 	char *vers;
@@ -1585,7 +1585,7 @@ static const struct net_device_ops ppp_netdev_ops = {
 	.ndo_init	 = ppp_dev_init,
 	.ndo_uninit      = ppp_dev_uninit,
 	.ndo_start_xmit  = ppp_start_xmit,
-	.ndo_do_ioctl    = ppp_net_ioctl,
+	.ndo_siocdevprivate = ppp_net_siocdevprivate,
 	.ndo_get_stats64 = ppp_get_stats64,
 	.ndo_fill_forward_path = ppp_fill_forward_path,
 };