staging: comedi: das1800: add missing break in switch

Commit 06ad6bd8 "staging: comedi: das1800: cleanup das1800_probe()"

Accidently removed the 'break' statement for case 0x8 of the switch.
Add it back.

Reported-by: coverity (CID 1309550)
Signed-off-by: NH Hartley Sweeten <hsweeten@visionengravers.com>
Reviewed-by: NIan Abbott <abbotti@mev.co.uk>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/comedi/drivers/das1800.c

@@ -1266,6 +1266,7 @@ static const struct das1800_board *das1800_probe(struct comedi_device *dev)
 		if (index == das1801hc || index == das1802hc)
 			return board;
 		index = das1801hc;
+		break;
 	default:
 		dev_err(dev->class_dev,
 			"Board model: probe returned 0x%x (unknown, please report)\n",