inet: rename some inet_sock fields

In order to have better cache layouts of struct sock (separate zones
for rx/tx paths), we need this preliminary patch.

Goal is to transfert fields used at lookup time in the first
read-mostly cache line (inside struct sock_common) and move sk_refcnt
to a separate cache line (only written by rx path)

This patch adds inet_ prefix to daddr, rcv_saddr, dport, num, saddr,
sport and id fields. This allows a future patch to define these
fields as macros, like sk_refcnt, without name clashes.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv6/ip6mr.c b/net/ipv6/ip6mr.c
index 7161539..85849b4 100644
--- a/net/ipv6/ip6mr.c
+++ b/net/ipv6/ip6mr.c
@@ -1297,7 +1297,7 @@
 	switch (optname) {
 	case MRT6_INIT:
 		if (sk->sk_type != SOCK_RAW ||
-		    inet_sk(sk)->num != IPPROTO_ICMPV6)
+		    inet_sk(sk)->inet_num != IPPROTO_ICMPV6)
 			return -EOPNOTSUPP;
 		if (optlen < sizeof(int))
 			return -EINVAL;