hwmon: (acpi_power_meter) Use return value from acpi_bus_register_driver

acpi_bus_register_driver() returns a valid error code. Use it.
Signed-off-by: Guenter Roeck <linux@roeck-us.net>

drivers/hwmon/acpi_power_meter.c

@@ -996,7 +996,7 @@ static int __init acpi_power_meter_init(void)
 
 	result = acpi_bus_register_driver(&acpi_power_meter_driver);
 	if (result < 0)
-		return -ENODEV;
+		return result;
 
 	return 0;
 }