netlink: fix description of portid

Avoid confusion between pid and portid.
Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/net/netlink.h

@@ -431,7 +431,7 @@ static inline int nlmsg_report(const struct nlmsghdr *nlh)
 /**
  * nlmsg_put - Add a new netlink message to an skb
  * @skb: socket buffer to store message in
- * @portid: netlink process id
+ * @portid: netlink PORTID of requesting application
  * @seq: sequence number of message
  * @type: message type
  * @payload: length of message payload