s390/sclp_cmd: replace PTR_RET with PTR_ERR_OR_ZERO

PTR_RET is deprecated. Do not recommend its usage anymore.
Use PTR_ERR_OR_ZERO instead.
Signed-off-by: NDuan Jiong <duanj.fnst@cn.fujitsu.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

drivers/s390/char/sclp_cmd.c

@@ -515,7 +515,7 @@ static int __init sclp_detect_standby_memory(void)
 	if (rc)
 		goto out;
 	sclp_pdev = platform_device_register_simple("sclp_mem", -1, NULL, 0);
-	rc = PTR_RET(sclp_pdev);
+	rc = PTR_ERR_OR_ZERO(sclp_pdev);
 	if (rc)
 		goto out_driver;
 	sclp_add_standby_memory();