platform/x86: hp-wireless: reuse module_acpi_driver

There is a macro to register and unregister modules in simple cases,
Let's use it and clean up the driver.

Cc: Alex Hung <alex.hung@canonical.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Darren Hart (VMware) <dvhart@infradead.org>

drivers/platform/x86/hp-wireless.c

@@ -110,21 +110,4 @@ static struct acpi_driver hpwl_driver = {
 	},
 };
 
-static int __init hpwl_init(void)
-{
-	int err;
-
-	err = acpi_bus_register_driver(&hpwl_driver);
-	if (err)
-		pr_err("Unable to register HP wireless control driver.\n");
-
-	return err;
-}
-
-static void __exit hpwl_exit(void)
-{
-	acpi_bus_unregister_driver(&hpwl_driver);
-}
-
-module_init(hpwl_init);
-module_exit(hpwl_exit);
+module_acpi_driver(hpwl_driver);