x86/platform/olpc: Use PTR_ERR_OR_ZERO()

Replace the open coded equivalent with PTR_ERR_OR_ZERO().
Signed-off-by: zhong jiang <zhongjiang@huawei.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/1533053286-34990-1-git-send-email-zhongjiang@huawei.com

arch/x86/platform/olpc/olpc.c

@@ -311,10 +311,8 @@ static int __init add_xo1_platform_devices(void)
 		return PTR_ERR(pdev);
 
 	pdev = platform_device_register_simple("olpc-xo1", -1, NULL, 0);
-	if (IS_ERR(pdev))
-		return PTR_ERR(pdev);
 
-	return 0;
+	return PTR_ERR_OR_ZERO(pdev);
 }
 
 static int olpc_xo1_ec_probe(struct platform_device *pdev)