[IPV6] ADDRCONF: Convert ipv6_get_saddr() to ipv6_dev_get_saddr().

Since most users of ipv6_get_saddr() pass non-NULL as
dst argument, use ipv6_dev_get_saddr() directly.

Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
diff --git a/net/ipv6/route.c b/net/ipv6/route.c
index 1b15e17..6abe7da 100644
--- a/net/ipv6/route.c
+++ b/net/ipv6/route.c
@@ -2122,7 +2122,8 @@
 		NLA_PUT_U32(skb, RTA_IIF, iif);
 	else if (dst) {
 		struct in6_addr saddr_buf;
-		if (ipv6_get_saddr(&rt->u.dst, dst, &saddr_buf) == 0)
+		if (ipv6_dev_get_saddr(ip6_dst_idev(&rt->u.dst)->dev,
+				       dst, &saddr_buf) == 0)
 			NLA_PUT(skb, RTA_PREFSRC, 16, &saddr_buf);
 	}