usb: gadget: uvc: use capped length value

"req->length" is a capped version of "data->length".
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>

drivers/usb/gadget/uvc_v4l2.c

@@ -42,7 +42,7 @@ uvc_send_response(struct uvc_device *uvc, struct uvc_request_data *data)
 	req->length = min_t(unsigned int, uvc->event_length, data->length);
 	req->zero = data->length < uvc->event_length;
 
-	memcpy(req->buf, data->data, data->length);
+	memcpy(req->buf, data->data, req->length);
 
 	return usb_ep_queue(cdev->gadget->ep0, req, GFP_KERNEL);
 }