net-sysfs: convert xps_cpus_show to bitmap_zalloc

Use bitmap_zalloc instead of zalloc_cpumask_var in xps_cpus_show to
align with xps_rxqs_show. This will improve maintenance and allow us to
factorize the two functions. The function should behave the same.
Signed-off-by: Antoine Tenart <atenart@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/core/net-sysfs.c

@@ -1367,8 +1367,7 @@ static ssize_t xps_cpus_show(struct netdev_queue *queue,
 	int cpu, len, ret, num_tc = 1, tc = 0;
 	struct net_device *dev = queue->dev;
 	struct xps_dev_maps *dev_maps;
-	cpumask_var_t mask;
-	unsigned long index;
+	unsigned long *mask, index;
 
 	if (!netif_is_multiqueue(dev))
 		return -ENOENT;
@@ -1396,7 +1395,8 @@ static ssize_t xps_cpus_show(struct netdev_queue *queue,
 		}
 	}
 
-	if (!zalloc_cpumask_var(&mask, GFP_KERNEL)) {
+	mask = bitmap_zalloc(nr_cpu_ids, GFP_KERNEL);
+	if (!mask) {
 		ret = -ENOMEM;
 		goto err_rtnl_unlock;
 	}
@@ -1414,7 +1414,7 @@ static ssize_t xps_cpus_show(struct netdev_queue *queue,
 
 			for (i = map->len; i--;) {
 				if (map->queues[i] == index) {
-					cpumask_set_cpu(cpu, mask);
+					set_bit(cpu, mask);
 					break;
 				}
 			}
@@ -1424,8 +1424,8 @@ static ssize_t xps_cpus_show(struct netdev_queue *queue,
 
 	rtnl_unlock();
 
-	len = snprintf(buf, PAGE_SIZE, "%*pb\n", cpumask_pr_args(mask));
-	free_cpumask_var(mask);
+	len = bitmap_print_to_pagebuf(false, buf, mask, nr_cpu_ids);
+	bitmap_free(mask);
 	return len < PAGE_SIZE ? len : -EINVAL;
 
 err_rtnl_unlock: