staging: comedi: rtd520: use comedi_buf_write_samples()

For aesthetics, use comedi_buf_write_samples() to add the sample to the
async buffer.
Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Reviewed-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/comedi/drivers/rtd520.c

@@ -623,7 +623,7 @@ static int ai_read_n(struct comedi_device *dev, struct comedi_subdevice *s,
 			d = comedi_offset_munge(s, d);
 		d &= s->maxdata;
 
-		if (!comedi_buf_put(s, d))
+		if (!comedi_buf_write_samples(s, &d, 1))
 			return -1;
 
 		if (devpriv->ai_count > 0)	/* < 0, means read forever */