iio: adc: ti_am335x_adc: remove omitted iio_kfifo_free()

When the conversion was done to use devm_iio_kfifo_allocate(), a call to
iio_kfifo_free() was omitted (to be removed).
This change removes it.

Fixes: 3c530805 ("iio: adc: ti_am335x_adc: alloc kfifo & IRQ via devm_ functions")
Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
Link: https://lore.kernel.org/r/20201203072650.24128-1-alexandru.ardelean@analog.com
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

drivers/iio/adc/ti_am335x_adc.c

@@ -397,16 +397,12 @@ static int tiadc_iio_buffered_hardware_setup(struct device *dev,
 	ret = devm_request_threaded_irq(dev, irq, pollfunc_th, pollfunc_bh,
 				flags, indio_dev->name, indio_dev);
 	if (ret)
-		goto error_kfifo_free;
+		return ret;
 
 	indio_dev->setup_ops = setup_ops;
 	indio_dev->modes |= INDIO_BUFFER_SOFTWARE;
 
 	return 0;
-
-error_kfifo_free:
-	iio_kfifo_free(indio_dev->buffer);
-	return ret;
 }
 
 static const char * const chan_name_ain[] = {