padata: use __this_cpu_read per-cpu helper

For bottom halves off, __this_cpu_read is better.

Signed-off-by: Shan Wei <[e-mail]>
Reviewed-by: Christoph Lameter <[e-mail]>
Acked-by: Steffen Klassert <[e-mail]>
Signed-off-by: Herbert Xu <[e-mail]>

kernel/padata.c

···
 {
 	int cpu, num_cpus;
 	unsigned int next_nr, next_index;
-	struct padata_parallel_queue *queue, *next_queue;
+	struct padata_parallel_queue *next_queue;
 	struct padata_priv *padata;
 	struct padata_list *reorder;
 
···
 		goto out;
 	}
 
-	queue = per_cpu_ptr(pd->pqueue, smp_processor_id());
-	if (queue->cpu_index == next_queue->cpu_index) {
+	if (__this_cpu_read(pd->pqueue->cpu_index) == next_queue->cpu_index) {
 		padata = ERR_PTR(-ENODATA);
 		goto out;
 	}