staging: comedi: call comedi_release_hardware_device() on error

If `comedi_auto_config()` fails after allocating the minor device, call
`comedi_release_hardware_device()` instead of
`comedi_free_board_minor()` to free the minor device.  That's the same
call that `comedi_auto_unconfig()` uses, and is slightly safer as it
checks the minor device number is still tied to the same hardware
device.
Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Reviewed-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/comedi/drivers.c

@@ -452,7 +452,7 @@ int comedi_auto_config(struct device *hardware_device,
 	mutex_unlock(&comedi_dev->mutex);
 
 	if (ret < 0)
-		comedi_free_board_minor(minor);
+		comedi_release_hardware_device(hardware_device);
 	return ret;
 }
 EXPORT_SYMBOL_GPL(comedi_auto_config);