staging:iio:docs: drop setting of THIS_MODULE from staging docs.

These docs need to be cleaned up properly, but for now lets drop
this entry as it is definitely no longer true.

Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Lars-Peter Clausen <lars@metafoo.de>

drivers/staging/iio/Documentation/device.txt

@@ -26,9 +26,6 @@ Then fill in the following:
 	pointer to a structure with elements that tend to be fixed for
 	large sets of different parts supported by a given driver.
 	This contains:
-	* info->driver_module:
-		Set to THIS_MODULE. Used to ensure correct ownership
-		of various resources allocate by the core.
 	* info->event_attrs:
 		Attributes used to enable / disable hardware events.
 	* info->attrs: