power: supply: lp8788: Fix an error handling path in 'lp8788_charger_probe()'

[ Upstream commit 934ed3847a4ebc75b655659c4d2349ba4337941c ]

In the probe function, in case of error, resources allocated in
'lp8788_setup_adc_channel()' must be released.

This can be achieved easily by using the devm_ variant of
'iio_channel_get()'.
This has the extra benefit to simplify the remove function and to axe the
'lp8788_release_adc_channel()' function which is now useless.

Fixes: 98a276649358 ("power_supply: Add new lp8788 charger driver")
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
diff --git a/drivers/power/supply/lp8788-charger.c b/drivers/power/supply/lp8788-charger.c
index 0f34327..b8f7dac 100644
--- a/drivers/power/supply/lp8788-charger.c
+++ b/drivers/power/supply/lp8788-charger.c
@@ -600,27 +600,14 @@
 		return;
 
 	/* ADC channel for battery voltage */
-	chan = iio_channel_get(dev, pdata->adc_vbatt);
+	chan = devm_iio_channel_get(dev, pdata->adc_vbatt);
 	pchg->chan[LP8788_VBATT] = IS_ERR(chan) ? NULL : chan;
 
 	/* ADC channel for battery temperature */
-	chan = iio_channel_get(dev, pdata->adc_batt_temp);
+	chan = devm_iio_channel_get(dev, pdata->adc_batt_temp);
 	pchg->chan[LP8788_BATT_TEMP] = IS_ERR(chan) ? NULL : chan;
 }
 
-static void lp8788_release_adc_channel(struct lp8788_charger *pchg)
-{
-	int i;
-
-	for (i = 0; i < LP8788_NUM_CHG_ADC; i++) {
-		if (!pchg->chan[i])
-			continue;
-
-		iio_channel_release(pchg->chan[i]);
-		pchg->chan[i] = NULL;
-	}
-}
-
 static ssize_t lp8788_show_charger_status(struct device *dev,
 				struct device_attribute *attr, char *buf)
 {
@@ -747,7 +734,6 @@
 	lp8788_irq_unregister(pdev, pchg);
 	sysfs_remove_group(&pdev->dev.kobj, &lp8788_attr_group);
 	lp8788_psy_unregister(pchg);
-	lp8788_release_adc_channel(pchg);
 
 	return 0;
 }