iio: backend: remove unused parameter

Indio_dev was not being used in iio_backend_extend_chan_spec() so remove
it.
Signed-off-by: Nuno Sa <nuno.sa@analog.com>
Link: https://patch.msgid.link/20240709-dev-iio-backend-add-debugfs-v1-1-fb4b8f2373c7@analog.comSigned-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

drivers/iio/dac/ad9739a.c

@@ -413,8 +413,7 @@ static int ad9739a_probe(struct spi_device *spi)
 	if (ret)
 		return ret;
 
-	ret = iio_backend_extend_chan_spec(indio_dev, st->back,
-					   &ad9739a_channels[0]);
+	ret = iio_backend_extend_chan_spec(st->back, &ad9739a_channels[0]);
 	if (ret)
 		return ret;
 

drivers/iio/industrialio-backend.c

@@ -451,7 +451,6 @@ EXPORT_SYMBOL_NS_GPL(iio_backend_ext_info_set, IIO_BACKEND);
 
 /**
  * iio_backend_extend_chan_spec - Extend an IIO channel
- * @indio_dev: IIO device
  * @back: Backend device
  * @chan: IIO channel
  *
@@ -461,8 +460,7 @@ EXPORT_SYMBOL_NS_GPL(iio_backend_ext_info_set, IIO_BACKEND);
  * RETURNS:
  * 0 on success, negative error number on failure.
  */
-int iio_backend_extend_chan_spec(struct iio_dev *indio_dev,
-				 struct iio_backend *back,
+int iio_backend_extend_chan_spec(struct iio_backend *back,
 				 struct iio_chan_spec *chan)
 {
 	const struct iio_chan_spec_ext_info *frontend_ext_info = chan->ext_info;

include/linux/iio/backend.h

@@ -142,8 +142,7 @@ ssize_t iio_backend_ext_info_set(struct iio_dev *indio_dev, uintptr_t private,
 ssize_t iio_backend_ext_info_get(struct iio_dev *indio_dev, uintptr_t private,
 				 const struct iio_chan_spec *chan, char *buf);
 
-int iio_backend_extend_chan_spec(struct iio_dev *indio_dev,
-				 struct iio_backend *back,
+int iio_backend_extend_chan_spec(struct iio_backend *back,
 				 struct iio_chan_spec *chan);
 void *iio_backend_get_priv(const struct iio_backend *conv);
 struct iio_backend *devm_iio_backend_get(struct device *dev, const char *name);