iio: adc: ad7923: 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/ad7923.c:159: warning: Function parameter or member 'indio_dev' not described in 'ad7923_update_scan_mode'
 drivers/iio/adc/ad7923.c:159: warning: Function parameter or member 'active_scan_mask' not described in 'ad7923_update_scan_mode'
 drivers/iio/adc/ad7923.c:202: warning: Function parameter or member 'irq' not described in 'ad7923_trigger_handler'
 drivers/iio/adc/ad7923.c:202: warning: Function parameter or member 'p' not described in 'ad7923_trigger_handler'

Cc: Michael Hennerich <Michael.Hennerich@analog.com>
Cc: Patrick Vasseur <patrick.vasseur@c-s.fr>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

drivers/iio/adc/ad7923.c

@@ -151,9 +151,9 @@ static const struct ad7923_chip_info ad7923_chip_info[] = {
 	},
 };
 
-/**
+/*
  * ad7923_update_scan_mode() setup the spi transfer buffer for the new scan mask
- **/
+ */
 static int ad7923_update_scan_mode(struct iio_dev *indio_dev,
 				   const unsigned long *active_scan_mask)
 {
@@ -192,12 +192,12 @@ static int ad7923_update_scan_mode(struct iio_dev *indio_dev,
 	return 0;
 }
 
-/**
+/*
  * ad7923_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 ad7923_trigger_handler(int irq, void *p)
 {
 	struct iio_poll_func *pf = p;