usb: gadget: udc-xilinx: Fix xudc_stop() kernel-doc format

The patch removes "driver" parameter which has been removed without
updating kernel-doc format.

Fixes: 22835b8 ("usb: gadget: remove unnecessary 'driver' argument")
Signed-off-by: Michal Simek <michal.simek@xilinx.com>
Link: https://lore.kernel.org/r/c753b529bdcdfdd40a3cf69121527ec8c63775cb.1581505183.git.michal.simek@xilinx.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/gadget/udc/udc-xilinx.c

@@ -1399,7 +1399,6 @@ static int xudc_start(struct usb_gadget *gadget,
 /**
  * xudc_stop - stops the device.
  * @gadget: pointer to the usb gadget structure
- * @driver: pointer to usb gadget driver structure
  *
  * Return: zero always
  */