[IPV4]: Fix secondary IP addresses after promotion

This patch fixes the problem with promoting aliases when:
a) a single primary and > 1 secondary addresses
b) multiple primary addresses each with at least one secondary address

Based on earlier efforts from Brian Pomerantz <bapper@piratehaven.org>,
Patrick McHardy <kaber@trash.net> and Thomas Graf <tgraf@suug.ch>

Signed-off-by: Jamal Hadi Salim <hadi@cyberus.ca>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv4/fib_frontend.c b/net/ipv4/fib_frontend.c
index 2267c1f..882f88f 100644
--- a/net/ipv4/fib_frontend.c
+++ b/net/ipv4/fib_frontend.c
@@ -407,7 +407,7 @@
 		tb->tb_delete(tb, &req.rtm, &rta, &req.nlh, NULL);
 }
 
-static void fib_add_ifaddr(struct in_ifaddr *ifa)
+void fib_add_ifaddr(struct in_ifaddr *ifa)
 {
 	struct in_device *in_dev = ifa->ifa_dev;
 	struct net_device *dev = in_dev->dev;