ppp: Cache net in pptp_xmit

Compute net and store it in a variable in pptp_xmit, so that the value
can be reused the next time it is needed.
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ppp/pptp.c

@@ -169,6 +169,7 @@ static int pptp_xmit(struct ppp_channel *chan, struct sk_buff *skb)
 {
 	struct sock *sk = (struct sock *) chan->private;
 	struct pppox_sock *po = pppox_sk(sk);
+	struct net *net = sock_net(sk);
 	struct pptp_opt *opt = &po->proto.pptp;
 	struct pptp_gre_header *hdr;
 	unsigned int header_len = sizeof(*hdr);
@@ -187,7 +188,7 @@ static int pptp_xmit(struct ppp_channel *chan, struct sk_buff *skb)
 	if (sk_pppox(po)->sk_state & PPPOX_DEAD)
 		goto tx_error;
 
-	rt = ip_route_output_ports(sock_net(sk), &fl4, NULL,
+	rt = ip_route_output_ports(net, &fl4, NULL,
 				   opt->dst_addr.sin_addr.s_addr,
 				   opt->src_addr.sin_addr.s_addr,
 				   0, 0, IPPROTO_GRE,
@@ -279,7 +280,7 @@ static int pptp_xmit(struct ppp_channel *chan, struct sk_buff *skb)
 	nf_reset(skb);
 
 	skb->ip_summed = CHECKSUM_NONE;
-	ip_select_ident(sock_net(sk), skb, NULL);
+	ip_select_ident(net, skb, NULL);
 	ip_send_check(iph);
 
 	ip_local_out(skb->sk, skb);