iio: gyro: hid-sensor-gyro-3d: 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/gyro/hid-sensor-gyro-3d.c

···
 	struct iio_dev *indio_dev;
 	struct gyro_3d_state *gyro_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(*gyro_state));
 	if (!indio_dev)
···
 		return ret;
 	}
 
-	channels = kmemdup(gyro_3d_channels, sizeof(gyro_3d_channels),
-			   GFP_KERNEL);
-	if (!channels) {
+	indio_dev->channels = kmemdup(gyro_3d_channels,
+				      sizeof(gyro_3d_channels), GFP_KERNEL);
+	if (!indio_dev->channels) {
 		dev_err(&pdev->dev, "failed to duplicate channels\n");
 		return -ENOMEM;
 	}
 
-	ret = gyro_3d_parse_report(pdev, hsdev, channels,
-					HID_USAGE_SENSOR_GYRO_3D, gyro_state);
+	ret = gyro_3d_parse_report(pdev, hsdev,
+				   (struct iio_chan_spec *)indio_dev->channels,
+				   HID_USAGE_SENSOR_GYRO_3D, gyro_state);
 	if (ret) {
 		dev_err(&pdev->dev, "failed to setup attributes\n");
 		goto error_free_dev_mem;
 	}
 
-	indio_dev->channels = channels;
 	indio_dev->num_channels = ARRAY_SIZE(gyro_3d_channels);
 	indio_dev->dev.parent = &pdev->dev;
 	indio_dev->info = &gyro_3d_info;