net: hisilicon: fix ptr_ret.cocci warnings

drivers/net/ethernet/hisilicon/hns/hnae.c:442:1-3: WARNING: PTR_ERR_OR_ZERO can be used

 Use PTR_ERR_OR_ZERO rather than if(IS_ERR(...)) + PTR_ERR

Generated by: scripts/coccinelle/api/ptr_ret.cocci

CC: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/hisilicon/hns/hnae.c

@@ -439,10 +439,7 @@ EXPORT_SYMBOL(hnae_ae_unregister);
 static int __init hnae_init(void)
 {
 	hnae_class = class_create(THIS_MODULE, "hnae");
-	if (IS_ERR(hnae_class))
-		return PTR_ERR(hnae_class);
-
-	return 0;
+	return PTR_ERR_OR_ZERO(hnae_class);
 }
 
 static void __exit hnae_exit(void)