staging: iio: ad9832: allocate data before using

The regulator changes assigned data to an uninitialized pointer:

drivers/staging/iio/frequency/ad9832.c: In function 'ad9832_probe':
drivers/staging/iio/frequency/ad9832.c:214:11: error: 'st' may be used uninitialized in this function [-Werror=maybe-uninitialized]

This moves the allocation of the 'st' structure before its first
use, as it should have been.

Fixes: 43a07e48af44 ("staging: iio: ad9832: clean-up regulator 'reg'")
Fixes: a98461d79ba5 ("staging: iio: ad9832: add DVDD regulator")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

drivers/staging/iio/frequency/ad9832.c

@@ -211,6 +211,13 @@ static int ad9832_probe(struct spi_device *spi)
 		return -ENODEV;
 	}
 
+	indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));
+	if (!indio_dev)
+		return -ENOMEM;
+
+	spi_set_drvdata(spi, indio_dev);
+	st = iio_priv(indio_dev);
+
 	st->avdd = devm_regulator_get(&spi->dev, "avdd");
 	if (IS_ERR(st->avdd))
 		return PTR_ERR(st->avdd);
@@ -233,13 +240,6 @@ static int ad9832_probe(struct spi_device *spi)
 		goto error_disable_avdd;
 	}
 
-	indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));
-	if (!indio_dev) {
-		ret = -ENOMEM;
-		goto error_disable_dvdd;
-	}
-	spi_set_drvdata(spi, indio_dev);
-	st = iio_priv(indio_dev);
 	st->mclk = pdata->mclk;
 	st->spi = spi;