staging:iio:dummy driver: Do not return error code in interrupt handler

The interrupt handler should only ever return one of the three irqreturn_t
constants and not an error code. Also make sure to always call
iio_trigger_notify_done before leaving the trigger handler.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

drivers/staging/iio/iio_simple_dummy_buffer.c

@@ -52,7 +52,7 @@ static irqreturn_t iio_simple_dummy_trigger_h(int irq, void *p)
 
 	data = kmalloc(indio_dev->scan_bytes, GFP_KERNEL);
 	if (data == NULL)
-		return -ENOMEM;
+		goto done;
 
 	if (!bitmap_empty(indio_dev->active_scan_mask, indio_dev->masklength)) {
 		/*
@@ -91,6 +91,7 @@ static irqreturn_t iio_simple_dummy_trigger_h(int irq, void *p)
 
 	kfree(data);
 
+done:
 	/*
 	 * Tell the core we are done with this trigger and ready for the
 	 * next one.