[IPV4]: Restore multipath routing after rt_next changes.

I forgot to test build this part of the networking code... Sorry guys.
This patch renames u.rt_next to u.dst.rt_next

Signed-off-by: Eric Dumazet <dada1@cosmosbay.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/ipv4/multipath_drr.c

@@ -143,7 +143,7 @@ static void drr_select_route(const struct flowi *flp,
 	result = NULL;
 	cur_min = NULL;
 	for (nh = rcu_dereference(first); nh;
-	     nh = rcu_dereference(nh->u.rt_next)) {
+	     nh = rcu_dereference(nh->u.dst.rt_next)) {
 		if ((nh->u.dst.flags & DST_BALANCED) != 0 &&
 		    multipath_comparekeys(&nh->fl, flp)) {
 			int nh_ifidx = nh->u.dst.dev->ifindex;

net/ipv4/multipath_random.c

@@ -74,7 +74,7 @@ static void random_select_route(const struct flowi *flp,
 
 	/* count all candidate */
 	for (rt = rcu_dereference(first); rt;
-	     rt = rcu_dereference(rt->u.rt_next)) {
+	     rt = rcu_dereference(rt->u.dst.rt_next)) {
 		if ((rt->u.dst.flags & DST_BALANCED) != 0 &&
 		    multipath_comparekeys(&rt->fl, flp))
 			++candidate_count;
@@ -90,7 +90,7 @@ static void random_select_route(const struct flowi *flp,
 		/* find chosen candidate and adjust GC data for all candidates
 		 * to ensure they stay in cache
 		 */
-		for (rt = first; rt; rt = rt->u.rt_next) {
+		for (rt = first; rt; rt = rt->u.dst.rt_next) {
 			if ((rt->u.dst.flags & DST_BALANCED) != 0 &&
 			    multipath_comparekeys(&rt->fl, flp)) {
 				rt->u.dst.lastuse = jiffies;

net/ipv4/multipath_rr.c

@@ -58,7 +58,7 @@ static void rr_select_route(const struct flowi *flp,
 	 */
 	result = NULL;
 	for (nh = rcu_dereference(first); nh;
-	     nh = rcu_dereference(nh->u.rt_next)) {
+	     nh = rcu_dereference(nh->u.dst.rt_next)) {
 		if ((nh->u.dst.flags & DST_BALANCED) != 0 &&
 		    multipath_comparekeys(&nh->fl, flp)) {
 			nh->u.dst.lastuse = jiffies;

net/ipv4/multipath_wrandom.c

@@ -167,7 +167,7 @@ static void wrandom_select_route(const struct flowi *flp,
 
 	/* collect all candidates and identify their weights */
 	for (rt = rcu_dereference(first); rt;
-	     rt = rcu_dereference(rt->u.rt_next)) {
+	     rt = rcu_dereference(rt->u.dst.rt_next)) {
 		if ((rt->u.dst.flags & DST_BALANCED) != 0 &&
 		    multipath_comparekeys(&rt->fl, flp)) {
 			struct multipath_candidate* mpc =