iio: adc: ad7298: Demote obvious misuse of kerneldoc to standard comment blocks

No attempt has been made to document either of the demoted functions here.

Fixes the following W=1 kernel build warning(s):

 drivers/iio/adc/ad7298.c:106: warning: Function parameter or member 'indio_dev' not described in 'ad7298_update_scan_mode'
 drivers/iio/adc/ad7298.c:106: warning: Function parameter or member 'active_scan_mask' not described in 'ad7298_update_scan_mode'
 drivers/iio/adc/ad7298.c:154: warning: Function parameter or member 'irq' not described in 'ad7298_trigger_handler'
 drivers/iio/adc/ad7298.c:154: warning: Function parameter or member 'p' not described in 'ad7298_trigger_handler'

Cc: Michael Hennerich <Michael.Hennerich@analog.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

drivers/iio/adc/ad7298.c

@@ -98,9 +98,9 @@ static const struct iio_chan_spec ad7298_channels[] = {
 	IIO_CHAN_SOFT_TIMESTAMP(8),
 };
 
-/**
+/*
  * ad7298_update_scan_mode() setup the spi transfer buffer for the new scan mask
- **/
+ */
 static int ad7298_update_scan_mode(struct iio_dev *indio_dev,
 	const unsigned long *active_scan_mask)
 {
@@ -144,12 +144,12 @@ static int ad7298_update_scan_mode(struct iio_dev *indio_dev,
 	return 0;
 }
 
-/**
+/*
  * ad7298_trigger_handler() bh of trigger launched polling to ring buffer
  *
  * Currently there is no option in this driver to disable the saving of
  * timestamps within the ring.
- **/
+ */
 static irqreturn_t ad7298_trigger_handler(int irq, void *p)
 {
 	struct iio_poll_func *pf = p;