staging:iio:impedance-analyzer: 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>

drivers/staging/iio/impedance-analyzer/ad5933.c

@@ -291,7 +291,7 @@ static ssize_t ad5933_show_frequency(struct device *dev,
 					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 ad5933_state *st = iio_priv(indio_dev);
 	struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
 	int ret;
@@ -320,7 +320,7 @@ static ssize_t ad5933_store_frequency(struct device *dev,
 					 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);
 	struct ad5933_state *st = iio_priv(indio_dev);
 	struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
 	long val;
@@ -354,7 +354,7 @@ static ssize_t ad5933_show(struct device *dev,
 					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 ad5933_state *st = iio_priv(indio_dev);
 	struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
 	int ret = 0, len = 0;
@@ -397,7 +397,7 @@ static ssize_t ad5933_store(struct device *dev,
 					 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);
 	struct ad5933_state *st = iio_priv(indio_dev);
 	struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
 	long val;