iio: orientation: hid-sensor-rotation: Fix memory leak in probe()

'channels' is allocated via kmemdup and it is never freed in the
subsequent error paths.

Use 'indio_dev->channels' directly instead, so that we avoid such
memory leak problem.

Signed-off-by: Fabio Estevam <[e-mail]>
Reviewed-by: Srinivas Pandruvada <[e-mail]>
Signed-off-by: Jonathan Cameron <[e-mail]>

drivers/iio/orientation/hid-sensor-rotation.c

···
 	struct iio_dev *indio_dev;
 	struct dev_rot_state *rot_state;
 	struct hid_sensor_hub_device *hsdev = pdev->dev.platform_data;
-	struct iio_chan_spec *channels;
 
 	indio_dev = devm_iio_device_alloc(&pdev->dev,
 					  sizeof(struct dev_rot_state));
···
 		return ret;
 	}
 
-	channels = devm_kmemdup(&pdev->dev, dev_rot_channels,
-					sizeof(dev_rot_channels), GFP_KERNEL);
-	if (!channels) {
+	indio_dev->channels = devm_kmemdup(&pdev->dev, dev_rot_channels,
+					   sizeof(dev_rot_channels),
+					   GFP_KERNEL);
+	if (!indio_dev->channels) {
 		dev_err(&pdev->dev, "failed to duplicate channels\n");
 		return -ENOMEM;
 	}
 
-	ret = dev_rot_parse_report(pdev, hsdev, channels,
-			HID_USAGE_SENSOR_DEVICE_ORIENTATION, rot_state);
+	ret = dev_rot_parse_report(pdev, hsdev,
+				   (struct iio_chan_spec *)indio_dev->channels,
+				   HID_USAGE_SENSOR_DEVICE_ORIENTATION,
+				   rot_state);
 	if (ret) {
 		dev_err(&pdev->dev, "failed to setup attributes\n");
 		return ret;
 	}
 
-	indio_dev->channels = channels;
 	indio_dev->num_channels = ARRAY_SIZE(dev_rot_channels);
 	indio_dev->dev.parent = &pdev->dev;
 	indio_dev->info = &dev_rot_info;