[NETLINK]: Introduce NLMSG_NEW macro to better handle netlink flags

Introduces a new macro NLMSG_NEW which extends NLMSG_PUT but takes
a flags argument. NLMSG_PUT stays there for compatibility but now
calls NLMSG_NEW with flags == 0. NLMSG_PUT_ANSWER is renamed to
NLMSG_NEW_ANSWER which now also takes a flags argument.

Also converts the users of NLMSG_PUT_ANSWER to use NLMSG_NEW_ANSWER
and fixes the two direct users of __nlmsg_put to either provide
the flags or use NLMSG_NEW(_ANSWER).

Signed-off-by: Thomas Graf <tgraf@suug.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/core/neighbour.c b/net/core/neighbour.c
index 2296a14..0fb742e 100644
--- a/net/core/neighbour.c
+++ b/net/core/neighbour.c
@@ -1590,8 +1590,8 @@
 	struct nlmsghdr *nlh;
 	struct ndtmsg *ndtmsg;
 
-	nlh = NLMSG_PUT_ANSWER(skb, cb, RTM_NEWNEIGHTBL, sizeof(struct ndtmsg));
-	nlh->nlmsg_flags |= NLM_F_MULTI;
+	nlh = NLMSG_NEW_ANSWER(skb, cb, RTM_NEWNEIGHTBL, sizeof(struct ndtmsg),
+			       NLM_F_MULTI);
 
 	ndtmsg = NLMSG_DATA(nlh);
 
@@ -1675,8 +1675,8 @@
 	struct ndtmsg *ndtmsg;
 	struct nlmsghdr *nlh;
 
-	nlh = NLMSG_PUT_ANSWER(skb, cb, RTM_NEWNEIGHTBL, sizeof(struct ndtmsg));
-	nlh->nlmsg_flags |= NLM_F_MULTI;
+	nlh = NLMSG_NEW_ANSWER(skb, cb, RTM_NEWNEIGHTBL, sizeof(struct ndtmsg),
+			       NLM_F_MULTI);
 
 	ndtmsg = NLMSG_DATA(nlh);