net: Kill sock->sk_protinfo

No more users, so it can now be removed.
Signed-off-by: David S. Miller <davem@davemloft.net>

include/net/sock.h

@@ -277,7 +277,6 @@ struct cg_proto;
   *	@sk_incoming_cpu: record cpu processing incoming packets
   *	@sk_txhash: computed flow hash for use on transmit
   *	@sk_filter: socket filtering instructions
-  *	@sk_protinfo: private area, net family specific, when not using slab
   *	@sk_timer: sock cleanup timer
   *	@sk_stamp: time stamp of last packet received
   *	@sk_tsflags: SO_TIMESTAMPING socket options
@@ -416,7 +415,6 @@ struct sock {
 	const struct cred	*sk_peer_cred;
 	long			sk_rcvtimeo;
 	long			sk_sndtimeo;
-	void			*sk_protinfo;
 	struct timer_list	sk_timer;
 	ktime_t			sk_stamp;
 	u16			sk_tsflags;

net/core/sock.c

@@ -2269,7 +2269,6 @@ static void sock_def_write_space(struct sock *sk)
 
 static void sock_def_destruct(struct sock *sk)
 {
-	kfree(sk->sk_protinfo);
 }
 
 void sk_send_sigurg(struct sock *sk)

net/sctp/socket.c

@@ -2121,12 +2121,6 @@ static int sctp_recvmsg(struct sock *sk, struct msghdr *msg, size_t len,
 	if (sp->subscribe.sctp_data_io_event)
 		sctp_ulpevent_read_sndrcvinfo(event, msg);
 
-#if 0
-	/* FIXME: we should be calling IP/IPv6 layers.  */
-	if (sk->sk_protinfo.af_inet.cmsg_flags)
-		ip_cmsg_recv(msg, skb);
-#endif
-
 	err = copied;
 
 	/* If skb's length exceeds the user's buffer, update the skb and