[DCCP]: Introduce dccp_ipv4_af_ops

And make the core DCCP code AF agnostic, just like TCP, now its time
to work on net/dccp/ipv6.c, we are close to the end!

Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/dccp/proto.c b/net/dccp/proto.c
index 8a6b2a9..7b30c12 100644
--- a/net/dccp/proto.c
+++ b/net/dccp/proto.c
@@ -254,7 +254,9 @@
 	int val;
 
 	if (level != SOL_DCCP)
-		return ip_setsockopt(sk, level, optname, optval, optlen);
+		return inet_csk(sk)->icsk_af_ops->setsockopt(sk, level,
+							     optname, optval,
+							     optlen);
 
 	if (optlen < sizeof(int))
 		return -EINVAL;
@@ -320,8 +322,9 @@
 	int val, len;
 
 	if (level != SOL_DCCP)
-		return ip_getsockopt(sk, level, optname, optval, optlen);
-
+		return inet_csk(sk)->icsk_af_ops->getsockopt(sk, level,
+							     optname, optval,
+							     optlen);
 	if (get_user(len, optlen))
 		return -EFAULT;