[NETFILTER]: Restore {ipt,ip6t,ebt}_LOG compatibility

The nfnetlink_log infrastructure changes broke compatiblity of the LOG
targets. They currently use whatever log backend was registered first,
which means that if ipt_ULOG was loaded first, no messages will be printed
to the ring buffer anymore.

Restore compatiblity by using the old log functions by default and only use
the nf_log backend if the user explicitly said so.

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/bridge/netfilter/ebt_log.c

@@ -166,7 +166,12 @@ static void ebt_log(const struct sk_buff *skb, unsigned int hooknr,
 	li.u.log.level = info->loglevel;
 	li.u.log.logflags = info->bitmask;
 
-	nf_log_packet(PF_BRIDGE, hooknr, skb, in, out, &li, info->prefix);
+	if (info->bitmask & EBT_LOG_NFLOG)
+		nf_log_packet(PF_BRIDGE, hooknr, skb, in, out, &li,
+		              info->prefix);
+	else
+		ebt_log_packet(PF_BRIDGE, hooknr, skb, in, out, &li,
+		               info->prefix);
 }
 
 static struct ebt_watcher log =