batman-adv: split out router from orig_node

For the network wide multi interface optimization there are different
routers for each outgoing interface (outgoing from the OGM perspective,
incoming for payload traffic). To reflect this, change the router and
associated data to a list of routers.

While at it, rename batadv_orig_node_get_router() to
batadv_orig_router_get() to follow the new naming scheme.

Signed-off-by: Simon Wunderlich <simon@open-mesh.com>
Signed-off-by: Marek Lindner <mareklindner@neomailbox.ch>
Signed-off-by: Antonio Quartulli <antonio@meshcoding.com>
diff --git a/net/batman-adv/distributed-arp-table.c b/net/batman-adv/distributed-arp-table.c
index 997ae6a..1d214cd 100644
--- a/net/batman-adv/distributed-arp-table.c
+++ b/net/batman-adv/distributed-arp-table.c
@@ -589,7 +589,8 @@
 		if (cand[i].type == BATADV_DAT_CANDIDATE_NOT_FOUND)
 			continue;
 
-		neigh_node = batadv_orig_node_get_router(cand[i].orig_node);
+		neigh_node = batadv_orig_router_get(cand[i].orig_node,
+						    BATADV_IF_DEFAULT);
 		if (!neigh_node)
 			goto free_orig;