use local_softirq_pending instead of softirq_pending in netif_rx_ni

Some architectures can optimize local_softirq_pending much better than softirq_pending(smp_processor_id()), and for all others the former is just a macro expanding to the later.

Also this is the last use of softirq_pending() in common code, once this is in we can soon kill the notation of beeing able to query other cpus softirq pending count.

@@ -1470,7 +1470,7 @@ int netif_rx_ni(struct sk_buff *skb)
 
 	preempt_disable();
 	err = netif_rx(skb);
-	if (softirq_pending(smp_processor_id()))
+	if (local_softirq_pending())
 		do_softirq();
 	preempt_enable();
 

Queued for 2.6.11, thanks Christoph.