documentation: local_ops fix on_each_cpu

Impact: update code example in documentation

* Dr. David Alan Gilbert ([e-mail]) wrote:
[...]
> I noticed while looking at something else that the example in
> local_ops.txt still has the 4 operand on_each_cpu in the latest git;
> I don't know the rest of the code around there very well so I thought
> it best to mention it rather than post a patch.

Reported-by: Dr. David Alan Gilbert <[e-mail]>
Signed-off-by: Mathieu Desnoyers <[e-mail]>
Signed-off-by: Ingo Molnar <[e-mail]>

Documentation/local_ops.txt

···
 	int cpu;
 
 	/* Increment the counters */
-	on_each_cpu(test_each, NULL, 0, 1);
+	on_each_cpu(test_each, NULL, 1);
 	/* Read all the counters */
 	printk("Counters read from CPU %d\n", smp_processor_id());
 	for_each_online_cpu(cpu) {