[NETNS]: Make arp code network namespace consistent.

Some calls in the arp.c have network namespace as an argument. Getting
init_net inside these functions is simply inconsistent. Fix this.
Signed-off-by: NDenis V. Lunev <den@openvz.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

net/ipv4/arp.c

@@ -973,13 +973,13 @@ static int arp_req_set_public(struct net *net, struct arpreq *r,
 	if (mask && mask != htonl(0xFFFFFFFF))
 		return -EINVAL;
 	if (!dev && (r->arp_flags & ATF_COM)) {
-		dev = dev_getbyhwaddr(&init_net, r->arp_ha.sa_family,
+		dev = dev_getbyhwaddr(net, r->arp_ha.sa_family,
 				r->arp_ha.sa_data);
 		if (!dev)
 			return -ENODEV;
 	}
 	if (mask) {
-		if (pneigh_lookup(&arp_tbl, &init_net, &ip, dev, 1) == NULL)
+		if (pneigh_lookup(&arp_tbl, net, &ip, dev, 1) == NULL)
 			return -ENOBUFS;
 		return 0;
 	}
@@ -1088,7 +1088,7 @@ static int arp_req_delete_public(struct net *net, struct arpreq *r,
 	__be32 mask = ((struct sockaddr_in *)&r->arp_netmask)->sin_addr.s_addr;
 
 	if (mask == htonl(0xFFFFFFFF))
-		return pneigh_delete(&arp_tbl, &init_net, &ip, dev);
+		return pneigh_delete(&arp_tbl, net, &ip, dev);
 
 	if (mask)
 		return -EINVAL;
@@ -1166,7 +1166,7 @@ int arp_ioctl(struct net *net, unsigned int cmd, void __user *arg)
 	rtnl_lock();
 	if (r.arp_dev[0]) {
 		err = -ENODEV;
-		if ((dev = __dev_get_by_name(&init_net, r.arp_dev)) == NULL)
+		if ((dev = __dev_get_by_name(net, r.arp_dev)) == NULL)
 			goto out;
 
 		/* Mmmm... It is wrong... ARPHRD_NETROM==0 */