usb: gadget: udc-xilinx: Remove the invalid comment

The function don't return value, remove the invalid comment.

Signed-off-by: Li Qiong <liqiong@nfschina.com>
Link: https://lore.kernel.org/r/20250314101639.424013-2-liqiong@nfschina.com


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>