iio: trigger: free trigger resource correctly

These stand-alone trigger drivers were using iio_trigger_put()
where they should have been using iio_trigger_free(). The
iio_trigger_put() adds a module_put which is bad since they
never did a module_get.

In the sysfs driver, module_get/put's are used as triggers are
added & removed. This extra module_put() occurs on an error path
in the probe routine (probably rare).

In the bfin-timer & interrupt trigger drivers, the module resources
are not explicitly managed, so it's doing a put on something that
was never get'd. It occurs on the probe error path and on the
remove path (not so rare).

Tested with the sysfs trigger driver.
The bfin & interrupt drivers were build tested & inspected only.

Signed-off-by: Alison Schofield <[e-mail]>
Signed-off-by: Jonathan Cameron <[e-mail]>

drivers/iio/trigger/iio-trig-interrupt.c

···
 	trig_info = kzalloc(sizeof(*trig_info), GFP_KERNEL);
 	if (!trig_info) {
 		ret = -ENOMEM;
-		goto error_put_trigger;
+		goto error_free_trigger;
 	}
 	iio_trigger_set_drvdata(trig, trig_info);
 	trig_info->irq = irq;
···
 	free_irq(irq, trig);
 error_free_trig_info:
 	kfree(trig_info);
-error_put_trigger:
-	iio_trigger_put(trig);
+error_free_trigger:
+	iio_trigger_free(trig);
 error_ret:
 	return ret;
 }
···
 	iio_trigger_unregister(trig);
 	free_irq(trig_info->irq, trig);
 	kfree(trig_info);
-	iio_trigger_put(trig);
+	iio_trigger_free(trig);
 
 	return 0;
 }

drivers/iio/trigger/iio-trig-sysfs.c

···
 	return 0;
 
 out2:
-	iio_trigger_put(t->trig);
+	iio_trigger_free(t->trig);
 free_t:
 	kfree(t);
 out1:

drivers/staging/iio/trigger/iio-trig-bfin-timer.c

···
 out1:
 	iio_trigger_unregister(st->trig);
 out:
-	iio_trigger_put(st->trig);
+	iio_trigger_free(st->trig);
 	return ret;
 }
 
···
 		peripheral_free(st->t->pin);
 	free_irq(st->irq, st);
 	iio_trigger_unregister(st->trig);
-	iio_trigger_put(st->trig);
+	iio_trigger_free(st->trig);
 
 	return 0;
 }