firmware: google memconsole: Fix return value check in platform_memconsole_init()

In case of error, the function platform_device_register_simple() returns
ERR_PTR() and never returns NULL. The NULL test in the return value
check should be replaced with IS_ERR().

Fixes: d384d6f4 ("firmware: google memconsole: Add coreboot support")
Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/firmware/google/memconsole-coreboot.c

@@ -95,8 +95,8 @@ static int __init platform_memconsole_init(void)
 	struct platform_device *pdev;
 
 	pdev = platform_device_register_simple("memconsole", -1, NULL, 0);
-	if (pdev == NULL)
-		return -ENODEV;
+	if (IS_ERR(pdev))
+		return PTR_ERR(pdev);
 
 	platform_driver_register(&memconsole_driver);