netlink: implement nla_put_in_addr and nla_put_in6_addr

IP addresses are often stored in netlink attributes. Add generic functions
to do that.

For nla_put_in_addr, it would be nicer to pass struct in_addr but this is
not used universally throughout the kernel, in way too many places __be32 is
used to store IPv4 address.

Signed-off-by: Jiri Benc <jbenc@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/wireless/nl80211.c

@@ -8761,8 +8761,8 @@ static int nl80211_send_wowlan_tcp(struct sk_buff *msg,
 	if (!nl_tcp)
 		return -ENOBUFS;
 
-	if (nla_put_be32(msg, NL80211_WOWLAN_TCP_SRC_IPV4, tcp->src) ||
-	    nla_put_be32(msg, NL80211_WOWLAN_TCP_DST_IPV4, tcp->dst) ||
+	if (nla_put_in_addr(msg, NL80211_WOWLAN_TCP_SRC_IPV4, tcp->src) ||
+	    nla_put_in_addr(msg, NL80211_WOWLAN_TCP_DST_IPV4, tcp->dst) ||
 	    nla_put(msg, NL80211_WOWLAN_TCP_DST_MAC, ETH_ALEN, tcp->dst_mac) ||
 	    nla_put_u16(msg, NL80211_WOWLAN_TCP_SRC_PORT, tcp->src_port) ||
 	    nla_put_u16(msg, NL80211_WOWLAN_TCP_DST_PORT, tcp->dst_port) ||