staging: comedi: comedi_test: use comedi_buf_write_samples()

Use comedi_buf_write_samples() instead of cfc_write_to_buffer() to add the
single 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/comedi_test.c

@@ -203,7 +203,7 @@ static void waveform_ai_interrupt(unsigned long arg)
 					       devpriv->usec_current +
 						   i * devpriv->scan_period +
 						   j * devpriv->convert_period);
-			cfc_write_to_buffer(s, sample);
+			comedi_buf_write_samples(s, &sample, 1);
 		}
 	}