HID: i2c-hid: Do not fail probing if gpiolib is not enabled

Using GPIOs and gpiolib is optional. If the kernel is compiled without GPIO
support the driver should not fail if it finds the interrupt using normal
methods.

However, commit a485923 ("HID: i2c-hid: Add support for ACPI GPIO
interrupts") did not take into account that acpi_dev_add_driver_gpios()
returns -ENXIO when !CONFIG_GPIOLIB.

Fix this by checking the return value against -ENXIO and 0 and only in that
case fail the probe.

Reported-by: Gabriele Mazzotta <gabriele.mzt@gmail.com>
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

drivers/hid/i2c-hid/i2c-hid.c

@@ -862,6 +862,7 @@ static int i2c_hid_acpi_pdata(struct i2c_client *client,
 	union acpi_object *obj;
 	struct acpi_device *adev;
 	acpi_handle handle;
+	int ret;
 
 	handle = ACPI_HANDLE(&client->dev);
 	if (!handle || acpi_bus_get_device(handle, &adev))
@@ -877,7 +878,9 @@ static int i2c_hid_acpi_pdata(struct i2c_client *client,
 	pdata->hid_descriptor_address = obj->integer.value;
 	ACPI_FREE(obj);
 
-	return acpi_dev_add_driver_gpios(adev, i2c_hid_acpi_gpios);
+	/* GPIOs are optional */
+	ret = acpi_dev_add_driver_gpios(adev, i2c_hid_acpi_gpios);
+	return ret < 0 && ret != -ENXIO ? ret : 0;
 }
 
 static const struct acpi_device_id i2c_hid_acpi_match[] = {