staging:iio:triggers Remove unecessary existence checks and return val

Postenable and predisable are called via buffer->ops so  don't
need to check if buffer exists.

The return value of iio_device_register_trigger_consumer is
always zero and it isn't checked anyway so get rid of it.
Signed-off-by: Jonathan Cameron <jic23@cam.ac.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/staging/iio/iio_core_trigger.h

@@ -13,8 +13,7 @@
  * iio_device_register_trigger_consumer() - set up an iio_dev to use triggers
  * @indio_dev: iio_dev associated with the device that will consume the trigger
  **/
-
-int iio_device_register_trigger_consumer(struct iio_dev *indio_dev);
+void iio_device_register_trigger_consumer(struct iio_dev *indio_dev);
 
 /**
  * iio_device_unregister_trigger_consumer() - reverse the registration process

drivers/staging/iio/industrialio-trigger.c

@@ -473,12 +473,10 @@ void iio_free_trigger(struct iio_trigger *trig)
 }
 EXPORT_SYMBOL(iio_free_trigger);
 
-int iio_device_register_trigger_consumer(struct iio_dev *indio_dev)
+void iio_device_register_trigger_consumer(struct iio_dev *indio_dev)
 {
 	indio_dev->groups[indio_dev->groupcounter++] =
 		&iio_trigger_consumer_attr_group;
-
-	return 0;
 }
 
 void iio_device_unregister_trigger_consumer(struct iio_dev *indio_dev)
@@ -490,18 +488,14 @@ void iio_device_unregister_trigger_consumer(struct iio_dev *indio_dev)
 
 int iio_triggered_buffer_postenable(struct iio_dev *indio_dev)
 {
-	return indio_dev->trig
-		? iio_trigger_attach_poll_func(indio_dev->trig,
-					       indio_dev->pollfunc)
-		: 0;
+	return iio_trigger_attach_poll_func(indio_dev->trig,
+					    indio_dev->pollfunc);
 }
 EXPORT_SYMBOL(iio_triggered_buffer_postenable);
 
 int iio_triggered_buffer_predisable(struct iio_dev *indio_dev)
 {
-	return indio_dev->trig
-		? iio_trigger_dettach_poll_func(indio_dev->trig,
-						indio_dev->pollfunc)
-		: 0;
+	return iio_trigger_dettach_poll_func(indio_dev->trig,
+					     indio_dev->pollfunc);
 }
 EXPORT_SYMBOL(iio_triggered_buffer_predisable);