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>
diff --git a/drivers/usb/gadget/uvc_v4l2.c b/drivers/usb/gadget/uvc_v4l2.c
index a6c728a..bb140dd 100644
--- a/drivers/usb/gadget/uvc_v4l2.c
+++ b/drivers/usb/gadget/uvc_v4l2.c
@@ -42,7 +42,7 @@
 	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);
 }