platform/x86: intel-vbtn: Switch to use devm_input_allocate_device

Use devm_input_allocate_device to simplify the error handling code.
This conversion also makes input_register_device() to be called after
acpi_remove_notify_handler. This avoid a small window that it's possible
to call notify_handler after unregister input device.
Signed-off-by: Axel Lin <axel.lin@ingics.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>

drivers/platform/x86/intel-vbtn.c

@@ -49,34 +49,19 @@ static int intel_vbtn_input_setup(struct platform_device *device)
 	struct intel_vbtn_priv *priv = dev_get_drvdata(&device->dev);
 	int ret;
 
-	priv->input_dev = input_allocate_device();
+	priv->input_dev = devm_input_allocate_device(&device->dev);
 	if (!priv->input_dev)
 		return -ENOMEM;
 
 	ret = sparse_keymap_setup(priv->input_dev, intel_vbtn_keymap, NULL);
 	if (ret)
-		goto err_free_device;
+		return ret;
 
 	priv->input_dev->dev.parent = &device->dev;
 	priv->input_dev->name = "Intel Virtual Button driver";
 	priv->input_dev->id.bustype = BUS_HOST;
 
-	ret = input_register_device(priv->input_dev);
-	if (ret)
-		goto err_free_device;
-
-	return 0;
-
-err_free_device:
-	input_free_device(priv->input_dev);
-	return ret;
-}
-
-static void intel_vbtn_input_destroy(struct platform_device *device)
-{
-	struct intel_vbtn_priv *priv = dev_get_drvdata(&device->dev);
-
-	input_unregister_device(priv->input_dev);
+	return input_register_device(priv->input_dev);
 }
 
 static void notify_handler(acpi_handle handle, u32 event, void *context)
@@ -117,24 +102,16 @@ static int intel_vbtn_probe(struct platform_device *device)
 					     ACPI_DEVICE_NOTIFY,
 					     notify_handler,
 					     device);
-	if (ACPI_FAILURE(status)) {
-		err = -EBUSY;
-		goto err_remove_input;
-	}
+	if (ACPI_FAILURE(status))
+		return -EBUSY;
 
 	return 0;
-
-err_remove_input:
-	intel_vbtn_input_destroy(device);
-
-	return err;
 }
 
 static int intel_vbtn_remove(struct platform_device *device)
 {
 	acpi_handle handle = ACPI_HANDLE(&device->dev);
 
-	intel_vbtn_input_destroy(device);
 	acpi_remove_notify_handler(handle, ACPI_DEVICE_NOTIFY, notify_handler);
 
 	/*