netfilter: bridge: clarify bridge/netfilter message

When using bridge without bridge netfilter enabled the message
displayed is rather confusing and leads to belive that a deprecated
feature is in use. Use IS_MODULE to be explicit that the message only
affects users which use bridge netfilter as module and reword the
message.
Signed-off-by: Stefan Agner <stefan@agner.ch>
Acked-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/bridge/br.c

@@ -227,9 +227,11 @@ static int __init br_init(void)
 	br_fdb_test_addr_hook = br_fdb_test_addr;
 #endif
 
-	pr_info("bridge: automatic filtering via arp/ip/ip6tables has been "
-		"deprecated. Update your scripts to load br_netfilter if you "
+#if IS_MODULE(CONFIG_BRIDGE_NETFILTER)
+	pr_info("bridge: filtering via arp/ip/ip6tables is no longer available "
+		"by default. Update your scripts to load br_netfilter if you "
 		"need this.\n");
+#endif
 
 	return 0;