net: Set sk_txhash from a random number

This patch creates sk_set_txhash and eliminates protocol specific
inet_set_txhash and ip6_set_txhash. sk_set_txhash simply sets a
random number instead of performing flow dissection. sk_set_txash
is also allowed to be called multiple times for the same socket,
we'll need this when redoing the hash for negative routing advice.

Signed-off-by: Tom Herbert <tom@herbertland.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv4/datagram.c b/net/ipv4/datagram.c
index 574fad9..f915abf 100644
--- a/net/ipv4/datagram.c
+++ b/net/ipv4/datagram.c
@@ -74,7 +74,7 @@
 	inet->inet_daddr = fl4->daddr;
 	inet->inet_dport = usin->sin_port;
 	sk->sk_state = TCP_ESTABLISHED;
-	inet_set_txhash(sk);
+	sk_set_txhash(sk);
 	inet->inet_id = jiffies;
 
 	sk_dst_set(sk, &rt->dst);