staging: iio: resolver: ad2s1210: fix use before initialization

This fixes a use before initialization in ad2s1210_probe(). The
ad2s1210_setup_gpios() function uses st->sdev but it was being called
before this field was initialized.
Signed-off-by: David Lechner <dlechner@baylibre.com>
Link: https://lore.kernel.org/r/20230929-ad2s1210-mainline-v3-2-fa4364281745@baylibre.comSigned-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

drivers/staging/iio/resolver/ad2s1210.c

@@ -658,9 +658,6 @@ static int ad2s1210_probe(struct spi_device *spi)
 	if (!indio_dev)
 		return -ENOMEM;
 	st = iio_priv(indio_dev);
-	ret = ad2s1210_setup_gpios(st);
-	if (ret < 0)
-		return ret;
 
 	spi_set_drvdata(spi, indio_dev);
 
@@ -671,6 +668,10 @@ static int ad2s1210_probe(struct spi_device *spi)
 	st->resolution = 12;
 	st->fexcit = AD2S1210_DEF_EXCIT;
 
+	ret = ad2s1210_setup_gpios(st);
+	if (ret < 0)
+		return ret;
+
 	indio_dev->info = &ad2s1210_info;
 	indio_dev->modes = INDIO_DIRECT_MODE;
 	indio_dev->channels = ad2s1210_channels;