btrfs: zoned: use vcalloc instead of for vzalloc in btrfs_get_dev_zone_info

Use vcalloc that checks potential multiplication overflows.  The changes
were done using Coccinelle semantic patch.
Reviewed-by: Naohiro Aota <naohiro.aota@wdc.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Julia Lawall <Julia.Lawall@inria.fr>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

fs/btrfs/zoned.c

@@ -465,8 +465,8 @@ int btrfs_get_dev_zone_info(struct btrfs_device *device, bool populate_cache)
 	 * use the cache.
 	 */
 	if (populate_cache && bdev_is_zoned(device->bdev)) {
-		zone_info->zone_cache = vzalloc(sizeof(struct blk_zone) *
-						zone_info->nr_zones);
+		zone_info->zone_cache = vcalloc(zone_info->nr_zones,
+						sizeof(struct blk_zone));
 		if (!zone_info->zone_cache) {
 			btrfs_err_in_rcu(device->fs_info,
 				"zoned: failed to allocate zone cache for %s",