[BRIDGE]: keep track of received multicast packets

It makes sense to add this simple statistic to keep track of received
multicast packets.

Signed-off-by: Stephen Hemminger <shemminger@osdl.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/bridge/br_input.c b/net/bridge/br_input.c
index b0b7f55..bfa4d8c 100644
--- a/net/bridge/br_input.c
+++ b/net/bridge/br_input.c
@@ -66,6 +66,7 @@
 	}
 
 	if (is_multicast_ether_addr(dest)) {
+		br->statistics.multicast++;
 		br_flood_forward(br, skb, !passedup);
 		if (!passedup)
 			br_pass_frame_up(br, skb);