connector - documentation: simplify netlink message length assignment

Use the precalculated size instead of obfuscating the message length
calculation by first subtracting the netlink header length from size
and then use the NLMSG_LENGTH() macro to add it back again.
Signed-off-by: Mathias Krause <minipli@googlemail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Documentation/connector/ucon.c

@@ -71,7 +71,7 @@ static int netlink_send(int s, struct cn_msg *msg)
 	nlh->nlmsg_seq = seq++;
 	nlh->nlmsg_pid = getpid();
 	nlh->nlmsg_type = NLMSG_DONE;
-	nlh->nlmsg_len = NLMSG_LENGTH(size - sizeof(*nlh));
+	nlh->nlmsg_len = size;
 	nlh->nlmsg_flags = 0;
 
 	m = NLMSG_DATA(nlh);