[NETNS]: Add netns parameter to fib_select_default.

Currently fib_select_default calls fib_get_table() with the
init_net. Prepare it to provide a correct namespace to lookup default
route.

Signed-off-by: Denis V. Lunev <den@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv4/route.c b/net/ipv4/route.c
index 27e0f81..4313255 100644
--- a/net/ipv4/route.c
+++ b/net/ipv4/route.c
@@ -2419,7 +2419,7 @@
 	else
 #endif
 	if (!res.prefixlen && res.type == RTN_UNICAST && !fl.oif)
-		fib_select_default(&fl, &res);
+		fib_select_default(&init_net, &fl, &res);
 
 	if (!fl.fl4_src)
 		fl.fl4_src = FIB_RES_PREFSRC(res);