mfd: kempld: Use PTR_ERR_OR_ZERO() to simplify code

Use the standard error pointer macro to shorten the code and simplify.

Signed-off-by: Xichao Zhao <zhao.xichao@vivo.com>
Link: https://lore.kernel.org/r/20250812093104.103193-1-zhao.xichao@vivo.com
Signed-off-by: Lee Jones <lee@kernel.org>

drivers/mfd/kempld-core.c

@@ -141,10 +141,8 @@ static int kempld_create_platform_device(const struct kempld_platform_data *pdat
 	};
 
 	kempld_pdev = platform_device_register_full(&pdevinfo);
-	if (IS_ERR(kempld_pdev))
-		return PTR_ERR(kempld_pdev);
 
-	return 0;
+	return PTR_ERR_OR_ZERO(kempld_pdev);
 }
 
 /**