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/tipc/netlink.c b/net/tipc/netlink.c
index 47a839d..6675914 100644
--- a/net/tipc/netlink.c
+++ b/net/tipc/netlink.c
@@ -62,7 +62,7 @@
 		rep_nlh = nlmsg_hdr(rep_buf);
 		memcpy(rep_nlh, req_nlh, hdr_space);
 		rep_nlh->nlmsg_len = rep_buf->len;
-		genlmsg_unicast(&init_net, rep_buf, NETLINK_CB(skb).pid);
+		genlmsg_unicast(&init_net, rep_buf, NETLINK_CB(skb).portid);
 	}
 
 	return 0;