usb: gadget: uvc: call uvc uvcg_warn on completed status instead of uvcg_info

usb: gadget: uvc: call uvc uvcg_warn on completed status instead of uvcg_info

Likewise to the uvcvideo hostside driver, this patch is changing the
usb_request message of an non zero completion handler call from dev_info
to dev_warn.

Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Michael Grzeschik <m.grzeschik@pengutronix.de>
Link: https://lore.kernel.org/r/20220529223848.105914-4-m.grzeschik@pengutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>