staging:iio:adc:ad799x removed unused headers.

Signed-off-by: Jonathan Cameron <jic23@cam.ac.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/staging/iio/adc/ad799x_core.c

@@ -23,11 +23,9 @@
  */
 
 #include <linux/interrupt.h>
-#include <linux/workqueue.h>
 #include <linux/device.h>
 #include <linux/kernel.h>
 #include <linux/sysfs.h>
-#include <linux/list.h>
 #include <linux/i2c.h>
 #include <linux/regulator/consumer.h>
 #include <linux/slab.h>

drivers/staging/iio/adc/ad799x_ring.c

@@ -10,7 +10,6 @@
  */
 
 #include <linux/interrupt.h>
-#include <linux/workqueue.h>
 #include <linux/device.h>
 #include <linux/slab.h>
 #include <linux/kernel.h>