staging/comedi: Remove if(); statement without effect

Smatch warns about:
staging/comedi/drivers/cb_pcidas64.c:3304 prep_ao_dma() warn: if();

So the check currently does nothing and can be removed, as indicated by
Ian.

Signed-off-by: Peter Huewe <peterhuewe@gmx.de>
Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/comedi/drivers/cb_pcidas64.c

@@ -3301,7 +3301,6 @@ static int prep_ao_dma(struct comedi_device *dev, const struct comedi_cmd *cmd)
 	num_bytes = load_ao_dma_buffer(dev, cmd);
 	if (num_bytes == 0)
 		return -1;
-	if (num_bytes >= DMA_BUFFER_SIZE) ;
 	load_ao_dma(dev, cmd);
 
 	dma_start_sync(dev, 0);