staging: comedi: dt2815: use comedi_request_region()

Use comedi_request_region() to request the I/O region used by this
driver.

Remove the noise when the board is first attached as well as the
error message when the request_region() fails, comedi_request_reqion()
will output the error message if necessary.

Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Cc: Ian Abbott <abbotti@mev.co.uk>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/comedi/drivers/dt2815.c

@@ -160,17 +160,11 @@ static int dt2815_attach(struct comedi_device *dev, struct comedi_devconfig *it)
 	struct comedi_subdevice *s;
 	int i;
 	const struct comedi_lrange *current_range_type, *voltage_range_type;
-	unsigned long iobase;
 	int ret;
 
-	iobase = it->options[0];
-	printk(KERN_INFO "comedi%d: dt2815: 0x%04lx ", dev->minor, iobase);
-	if (!request_region(iobase, DT2815_SIZE, "dt2815")) {
-		printk(KERN_WARNING "I/O port conflict\n");
-		return -EIO;
-	}
-
-	dev->iobase = iobase;
+	ret = comedi_request_region(dev, it->options[0], DT2815_SIZE);
+	if (ret)
+		return ret;
 
 	ret = comedi_alloc_subdevices(dev, 1);
 	if (ret)