netlink: Rename pid to portid to avoid confusion

It is a frequent mistake to confuse the netlink port identifier with a
process identifier.  Try to reduce this confusion by renaming fields
that hold port identifiers portid instead of pid.

I have carefully avoided changing the structures exported to
userspace to avoid changing the userspace API.

I have successfully built an allyesconfig kernel with this change.

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Acked-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c
index 508c5df..9257537 100644
--- a/net/core/rtnetlink.c
+++ b/net/core/rtnetlink.c
@@ -1081,7 +1081,7 @@
 			if (idx < s_idx)
 				goto cont;
 			if (rtnl_fill_ifinfo(skb, dev, RTM_NEWLINK,
-					     NETLINK_CB(cb->skb).pid,
+					     NETLINK_CB(cb->skb).portid,
 					     cb->nlh->nlmsg_seq, 0,
 					     NLM_F_MULTI,
 					     ext_filter_mask) <= 0)
@@ -1899,14 +1899,14 @@
 	if (nskb == NULL)
 		return -ENOBUFS;
 
-	err = rtnl_fill_ifinfo(nskb, dev, RTM_NEWLINK, NETLINK_CB(skb).pid,
+	err = rtnl_fill_ifinfo(nskb, dev, RTM_NEWLINK, NETLINK_CB(skb).portid,
 			       nlh->nlmsg_seq, 0, 0, ext_filter_mask);
 	if (err < 0) {
 		/* -EMSGSIZE implies BUG in if_nlmsg_size */
 		WARN_ON(err == -EMSGSIZE);
 		kfree_skb(nskb);
 	} else
-		err = rtnl_unicast(nskb, net, NETLINK_CB(skb).pid);
+		err = rtnl_unicast(nskb, net, NETLINK_CB(skb).portid);
 
 	return err;
 }
@@ -2180,9 +2180,9 @@
 {
 	struct netdev_hw_addr *ha;
 	int err;
-	u32 pid, seq;
+	u32 portid, seq;
 
-	pid = NETLINK_CB(cb->skb).pid;
+	portid = NETLINK_CB(cb->skb).portid;
 	seq = cb->nlh->nlmsg_seq;
 
 	list_for_each_entry(ha, &list->list, list) {
@@ -2190,7 +2190,7 @@
 			goto skip;
 
 		err = nlmsg_populate_fdb_fill(skb, dev, ha->addr,
-					      pid, seq, 0, NTF_SELF);
+					      portid, seq, 0, NTF_SELF);
 		if (err < 0)
 			return err;
 skip: