[NETFILTER]: nfnetlink_log: fix reference leak

Stop reference leaking in nfulnl_log_packet(). If we start a timer we
are already taking another reference.
Signed-off-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: Adrian Bunk <bunk@stusta.de>

net/netfilter/nfnetlink_log.c

@@ -687,15 +687,16 @@ nfulnl_log_packet(unsigned int pf,
 		inst->timer.expires = jiffies + (inst->flushtimeout*HZ/100);
 		add_timer(&inst->timer);
 	}
-	spin_unlock_bh(&inst->lock);
 
+unlock_and_release:
+	spin_unlock_bh(&inst->lock);
+	instance_put(inst);
 	return;
 
 alloc_failure:
-	spin_unlock_bh(&inst->lock);
-	instance_put(inst);
 	UDEBUG("error allocating skb\n");
 	/* FIXME: statistics */
+	goto unlock_and_release;
 }
 
 static int