iio: Remove obsolete variable in tcs3472 driver

len variable became obsolete with
iio_push_to_buffers_with_timestamp()

Signed-off-by: Peter Meerwald <[e-mail]>
Signed-off-by: Jonathan Cameron <[e-mail]>

drivers/iio/light/tcs3472.c

···
 	struct iio_poll_func *pf = p;
 	struct iio_dev *indio_dev = pf->indio_dev;
 	struct tcs3472_data *data = iio_priv(indio_dev);
-	int len = 0;
 	int i, j = 0;
 
 	int ret = tcs3472_req_data(data);
···
 			goto done;
 
 		data->buffer[j++] = ret;
-		len += 2;
 	}
 
 	iio_push_to_buffers_with_timestamp(indio_dev, data->buffer,