staging: comedi: amplc_dio200: dio200_common_attach() return 0

Change the successful return value of `dio200_common_attach()` from 1 to
0.  This is propagated as the return value from the driver's "attach"
(`dio200_attach()`) or "auto_attach" (`dio200_auto_attach()`) handler.
Any non-negative value will do, but 0 is more conventional than 1.
Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/comedi/drivers/amplc_dio200.c

@@ -1803,7 +1803,7 @@ static int dio200_common_attach(struct comedi_device *dev, unsigned int irq,
 		}
 	}
 	dio200_report_attach(dev, irq);
-	return 1;
+	return 0;
 }
 
 /* Only called for ISA boards. */