iio: kfifo: Remove unused argument in iio_kfifo_allocate

indio_dev was unused in function body plus some small style fix - add new
lines after "if(sth) return sth" and before the last return statement.

The argument was removed also in its client.

Signed-off-by: Karol Wrona <k.wrona@samsung.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

drivers/iio/adc/ti_am335x_adc.c

@@ -250,7 +250,7 @@ static int tiadc_iio_buffered_hardware_setup(struct iio_dev *indio_dev,
 	struct iio_buffer *buffer;
 	int ret;
 
-	buffer = iio_kfifo_allocate(indio_dev);
+	buffer = iio_kfifo_allocate();
 	if (!buffer)
 		return -ENOMEM;