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/ipv4/route.c b/net/ipv4/route.c
index d39edf1..940f4f4 100644
--- a/net/ipv4/route.c
+++ b/net/ipv4/route.c
@@ -2136,7 +2136,7 @@
 EXPORT_SYMBOL_GPL(ip_route_output_flow);
 
 static int rt_fill_info(struct net *net,  __be32 dst, __be32 src,
-			struct flowi4 *fl4, struct sk_buff *skb, u32 pid,
+			struct flowi4 *fl4, struct sk_buff *skb, u32 portid,
 			u32 seq, int event, int nowait, unsigned int flags)
 {
 	struct rtable *rt = skb_rtable(skb);
@@ -2146,7 +2146,7 @@
 	u32 error;
 	u32 metrics[RTAX_MAX];
 
-	nlh = nlmsg_put(skb, pid, seq, event, sizeof(*r), flags);
+	nlh = nlmsg_put(skb, portid, seq, event, sizeof(*r), flags);
 	if (nlh == NULL)
 		return -EMSGSIZE;
 
@@ -2306,12 +2306,12 @@
 		rt->rt_flags |= RTCF_NOTIFY;
 
 	err = rt_fill_info(net, dst, src, &fl4, skb,
-			   NETLINK_CB(in_skb).pid, nlh->nlmsg_seq,
+			   NETLINK_CB(in_skb).portid, nlh->nlmsg_seq,
 			   RTM_NEWROUTE, 0, 0);
 	if (err <= 0)
 		goto errout_free;
 
-	err = rtnl_unicast(skb, net, NETLINK_CB(in_skb).pid);
+	err = rtnl_unicast(skb, net, NETLINK_CB(in_skb).portid);
 errout:
 	return err;