ipv6: raw: rcu annotations

Remove sparse warnings, using a function typedef to be able to use __rcu
annotation on mh_filter pointer.
Signed-off-by: NEric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

net/ipv6/raw.c

@@ -123,18 +123,18 @@ static __inline__ int icmpv6_filter(struct sock *sk, struct sk_buff *skb)
 }
 
 #if defined(CONFIG_IPV6_MIP6) || defined(CONFIG_IPV6_MIP6_MODULE)
-static int (*mh_filter)(struct sock *sock, struct sk_buff *skb);
+typedef int mh_filter_t(struct sock *sock, struct sk_buff *skb);
 
-int rawv6_mh_filter_register(int (*filter)(struct sock *sock,
-					   struct sk_buff *skb))
+static mh_filter_t __rcu *mh_filter __read_mostly;
+
+int rawv6_mh_filter_register(mh_filter_t filter)
 {
 	rcu_assign_pointer(mh_filter, filter);
 	return 0;
 }
 EXPORT_SYMBOL(rawv6_mh_filter_register);
 
-int rawv6_mh_filter_unregister(int (*filter)(struct sock *sock,
-					     struct sk_buff *skb))
+int rawv6_mh_filter_unregister(mh_filter_t filter)
 {
 	rcu_assign_pointer(mh_filter, NULL);
 	synchronize_rcu();
@@ -192,10 +192,10 @@ static int ipv6_raw_deliver(struct sk_buff *skb, int nexthdr)
 			 * policy is placed in rawv6_rcv() because it is
 			 * required for each socket.
 			 */
-			int (*filter)(struct sock *sock, struct sk_buff *skb);
+			mh_filter_t *filter;
 
 			filter = rcu_dereference(mh_filter);
-			filtered = filter ? filter(sk, skb) : 0;
+			filtered = filter ? (*filter)(sk, skb) : 0;
 			break;
 		}
 #endif