pps: clients: gpio: Propagate return value from pps_gpio_probe

If the pps-gpio driver was probed prior to the GPIO device it uses, the
devm_gpiod_get call returned an -EPROBE_DEFER error, but pps_gpio_probe
replaced that error code with -EINVAL, causing the pps-gpio probe to
fail and not be retried later. Propagate the error return value so that
deferred probe works properly.

Fixes: 16152045 (pps: new client driver using GPIO)
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Rodolfo Giometti <giometti@enneenne.com>
Signed-off-by: Robert Hancock <robert.hancock@calian.com>
Signed-off-by: Rodolfo Giometti <giometti@enneenne.com>
Link: https://lore.kernel.org/r/20220112205214.2060954-1-robert.hancock@calian.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/pps/clients/pps-gpio.c

@@ -169,7 +169,7 @@ static int pps_gpio_probe(struct platform_device *pdev)
 	/* GPIO setup */
 	ret = pps_gpio_setup(dev);
 	if (ret)
-		return -EINVAL;
+		return ret;
 
 	/* IRQ setup */
 	ret = gpiod_to_irq(data->gpio_pin);