staging: comedi: das16: remove an unnecessary check in the attach

If the user does not specify the analog output range the private data
'user_ao_range_table' will not be allocated. The comedi core will detect
the NULL s->range_table and automatically set it to &range_unknown.
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/das16.c

@@ -1148,11 +1148,7 @@ static int das16_attach(struct comedi_device *dev, struct comedi_devconfig *it)
 		s->subdev_flags	= SDF_WRITABLE;
 		s->n_chan	= 2;
 		s->maxdata	= 0x0fff;
-		if (devpriv->user_ao_range_table)
-			s->range_table	= devpriv->user_ao_range_table;
-		else
-			s->range_table	= &range_unknown;
-
+		s->range_table	= devpriv->user_ao_range_table;
 		s->insn_write	= das16_ao_insn_write;
 	} else {
 		s->type		= COMEDI_SUBD_UNUSED;