net: clean up codestyle for net/ipv4

This is a pure codestyle cleanup patch. Also add a blank line after
declarations as warned by checkpatch.pl.

Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/ipv4/route.c

@@ -1079,7 +1079,7 @@ EXPORT_SYMBOL_GPL(ipv4_update_pmtu);
 
 static void __ipv4_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, u32 mtu)
 {
-	const struct iphdr *iph = (const struct iphdr *) skb->data;
+	const struct iphdr *iph = (const struct iphdr *)skb->data;
 	struct flowi4 fl4;
 	struct rtable *rt;
 
@@ -1127,7 +1127,7 @@ void ipv4_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, u32 mtu)
 		new = true;
 	}
 
-	__ip_rt_update_pmtu((struct rtable *) xfrm_dst_path(&rt->dst), &fl4, mtu);
+	__ip_rt_update_pmtu((struct rtable *)xfrm_dst_path(&rt->dst), &fl4, mtu);
 
 	if (!dst_check(&rt->dst, 0)) {
 		if (new)
@@ -1168,7 +1168,7 @@ EXPORT_SYMBOL_GPL(ipv4_redirect);
 
 void ipv4_sk_redirect(struct sk_buff *skb, struct sock *sk)
 {
-	const struct iphdr *iph = (const struct iphdr *) skb->data;
+	const struct iphdr *iph = (const struct iphdr *)skb->data;
 	struct flowi4 fl4;
 	struct rtable *rt;
 	struct net *net = sock_net(sk);