hwmon: (iio_hwmon) Fix missing iio_channel_release_all call if devm_kzalloc fail

Signed-off-by: Axel Lin <axel.lin@ingics.com>
Acked-by: Jonathan Cameron <jic23@kernel.org>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
diff --git a/drivers/hwmon/iio_hwmon.c b/drivers/hwmon/iio_hwmon.c
index aafa453..368497f 100644
--- a/drivers/hwmon/iio_hwmon.c
+++ b/drivers/hwmon/iio_hwmon.c
@@ -84,8 +84,10 @@
 		return PTR_ERR(channels);
 
 	st = devm_kzalloc(dev, sizeof(*st), GFP_KERNEL);
-	if (st == NULL)
-		return -ENOMEM;
+	if (st == NULL) {
+		ret = -ENOMEM;
+		goto error_release_channels;
+	}
 
 	st->channels = channels;