staging:iio:dac: Use dev_to_iio_dev()

Replace open-coded instances of getting a iio_dev struct from a device struct
with dev_to_iio_dev().

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Acked-by: Jonathan Cameron <jic23@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/drivers/staging/iio/dac/ad5360.c b/drivers/staging/iio/dac/ad5360.c
index 26cac42..38660ef 100644
--- a/drivers/staging/iio/dac/ad5360.c
+++ b/drivers/staging/iio/dac/ad5360.c
@@ -251,7 +251,7 @@
 					   struct device_attribute *attr,
 					   char *buf)
 {
-	struct iio_dev *indio_dev = dev_get_drvdata(dev);
+	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
 	struct ad5360_state *st = iio_priv(indio_dev);
 
 	return sprintf(buf, "%d\n", (bool)(st->ctrl & AD5360_SF_CTRL_PWR_DOWN));
@@ -279,7 +279,7 @@
 static ssize_t ad5360_write_dac_powerdown(struct device *dev,
 	struct device_attribute *attr, const char *buf, size_t len)
 {
-	struct iio_dev *indio_dev = dev_get_drvdata(dev);
+	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
 	bool pwr_down;
 	int ret;