[NETFILTER]: nfnetlink_log: micro-optimization: inst->skb != NULL in __nfulnl_send()

No other function calls __nfulnl_send() with inst->skb == NULL than
nfulnl_timer().
Signed-off-by: NMichal Miroslaw <mirq-linux@rere.qmqm.pl>
Signed-off-by: NPatrick McHardy <kaber@trash.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

net/netfilter/nfnetlink_log.c

@@ -360,9 +360,6 @@ __nfulnl_send(struct nfulnl_instance *inst)
 {
 	int status;
 
-	if (!inst->skb)
-		return 0;
-
 	if (inst->qlen > 1)
 		inst->lastnlh->nlmsg_type = NLMSG_DONE;
 
@@ -386,6 +383,7 @@ static void nfulnl_timer(unsigned long data)
 	UDEBUG("timer function called, flushing buffer\n");
 
 	spin_lock_bh(&inst->lock);
+	if (inst->skb)
 		__nfulnl_send(inst);
 	spin_unlock_bh(&inst->lock);
 	instance_put(inst);