Call local_update_neighbour from update_neighbour_metric.

This fixes a bug where we forgot to call local_update_neighbour
when receiving an IHU.  Reported by Gabriel Kerneis.

message.c

@@ -231,10 +231,12 @@ parse_packet(const unsigned char *from, struct network *net,
                    format_address(from), net->ifname,
                    format_address(address));
             if(message[2] == 0 || network_ll_address(net, address)) {
+                int changed = txcost != neigh->txcost;
                 neigh->txcost = txcost;
                 neigh->ihu_time = now;
                 neigh->ihu_interval = interval;
-                update_neighbour_metric(neigh);
+                if(changed)
+                    update_neighbour_metric(neigh);
                 if(interval > 0)
                     schedule_neighbours_check(interval * 10 * 3, 0);
             }

neighbour.c

@@ -105,7 +105,8 @@ find_neighbour(const unsigned char *address, struct network *net)
     return neigh;
 }
 
-/* Recompute a neighbour's rxcost.  Return true if anything changed. */
+/* Recompute a neighbour's rxcost.  Return true if anything changed.
+   This does not call local_notify_neighbour, see update_neighbour_metric. */
 int
 update_neighbour(struct neighbour *neigh, int hello, int hello_interval)
 {
@@ -190,8 +191,6 @@ update_neighbour(struct neighbour *neigh, int hello, int hello_interval)
         send_unicast_request(neigh, NULL, 0);
         send_ihu(neigh, NULL);
     }
-    if(rc)
-        local_notify_neighbour(neigh, LOCAL_CHANGE);
     return rc;
 }
 
@@ -248,10 +247,8 @@ check_neighbours()
         rc = reset_txcost(neigh);
         changed = changed || rc;
 
-        if(changed) {
+        if(changed)
             update_neighbour_metric(neigh);
-            local_notify_neighbour(neigh, LOCAL_CHANGE);
-        }
 
         if(neigh->hello_interval > 0)
             msecs = MIN(msecs, neigh->hello_interval * 10);

route.c

@@ -361,6 +361,8 @@ update_route_metric(struct route *route)
     }
 }
 
+/* Called whenever a neighbour's cost changes, to update the metric of
+   all routes through that neighbour.  Calls local_notify_neighbour. */
 void
 update_neighbour_metric(struct neighbour *neigh)
 {
@@ -372,6 +374,7 @@ update_neighbour_metric(struct neighbour *neigh)
             update_route_metric(&routes[i]);
         i++;
     }
+    local_notify_neighbour(neigh, LOCAL_CHANGE);
 }
 
 void