staging: comedi: ni_at_a2150: 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.

The core will add the COMEDI_CB_BLOCK event when data is written to the
async buffer. Remove the unnecessary event in the driver.
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/ni_at_a2150.c

@@ -237,7 +237,7 @@ static irqreturn_t a2150_interrupt(int irq, void *d)
 		dpnt = devpriv->dma_buffer[i];
 		/*  convert from 2's complement to unsigned coding */
 		dpnt ^= 0x8000;
-		cfc_write_to_buffer(s, dpnt);
+		comedi_buf_write_samples(s, &dpnt, 1);
 		if (cmd->stop_src == TRIG_COUNT) {
 			if (--devpriv->count == 0) {	/* end of acquisition */
 				async->events |= COMEDI_CB_EOA;
@@ -253,8 +253,6 @@ static irqreturn_t a2150_interrupt(int irq, void *d)
 	}
 	release_dma_lock(flags);
 
-	async->events |= COMEDI_CB_BLOCK;
-
 	comedi_handle_events(dev, s);
 
 	/* clear interrupt */