extcon: adc-jack: Fix an error handling path in 'adc_jack_probe()'

In some error handling paths, a call to 'iio_channel_get()' is not balanced
by a corresponding call to 'iio_channel_release()'.

This can be achieved easily by using the devm_ variant of
'iio_channel_get()'.

This has the extra benefit to simplify the remove function.

Fixes: 19939860dcae ("extcon: adc_jack: adc-jack driver to support 3.5 pi or simliar devices")
Signed-off-by: Christophe JAILLET <[e-mail]>
Signed-off-by: Chanwoo Choi <[e-mail]>

drivers/extcon/extcon-adc-jack.c

···
 	for (i = 0; data->adc_conditions[i].id != EXTCON_NONE; i++);
 	data->num_conditions = i;
 
-	data->chan = iio_channel_get(&pdev->dev, pdata->consumer_channel);
+	data->chan = devm_iio_channel_get(&pdev->dev, pdata->consumer_channel);
 	if (IS_ERR(data->chan))
 		return PTR_ERR(data->chan);
 
···
 
 	free_irq(data->irq, data);
 	cancel_work_sync(&data->handler.work);
-	iio_channel_release(data->chan);
 
 	return 0;
 }