iio:trigger: modify return value for iio_trigger_get

Instead of a void function, return the trigger pointer.

Whilst not in of itself a fix, this makes the following set of
7 fixes cleaner than they would otherwise be.

Signed-off-by: Srinivas Pandruvada <[e-mail]>
Signed-off-by: Jonathan Cameron <[e-mail]>
Cc: [e-mail]

include/linux/iio/trigger.h

···
 	put_device(&trig->dev);
 }
 
-static inline void iio_trigger_get(struct iio_trigger *trig)
+static inline struct iio_trigger *iio_trigger_get(struct iio_trigger *trig)
 {
 	get_device(&trig->dev);
 	__module_get(trig->ops->owner);
+
+	return trig;
 }
 
 /**