iio: code: mark iio_dev as const in iio_buffer_enabled

The iio_dev struct is never modified inside the method, mark it as
const.
This allows to be called from get_current_scan_type, and is useful
when the scan_type depends on the buffer state.

Signed-off-by: Jorge Marques <jorge.marques@analog.com>

Author: gastmaier

drivers/iio/industrialio-core.c

@@ -207,7 +207,7 @@ EXPORT_SYMBOL_GPL(iio_device_id);
  *
  * Returns: True, if the buffer is enabled.
  */
-bool iio_buffer_enabled(struct iio_dev *indio_dev)
+bool iio_buffer_enabled(const struct iio_dev *indio_dev)
 {
 	struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
 

include/linux/iio/iio.h

@@ -633,7 +633,7 @@ struct iio_dev {
 
 int iio_device_id(struct iio_dev *indio_dev);
 int iio_device_get_current_mode(struct iio_dev *indio_dev);
-bool iio_buffer_enabled(struct iio_dev *indio_dev);
+bool iio_buffer_enabled(const struct iio_dev *indio_dev);
 
 const struct iio_chan_spec
 *iio_find_channel_from_si(struct iio_dev *indio_dev, int si);