[media] uvcvideo: Use memdup_user() rather than duplicating its implementation

Reuse existing functionality from memdup_user() instead of keeping
duplicate source code.

This issue was detected by using the Coccinelle software.
Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

drivers/media/usb/uvc/uvc_v4l2.c

@@ -70,14 +70,9 @@ static int uvc_ioctl_ctrl_map(struct uvc_video_chain *chain,
 		}
 
 		size = xmap->menu_count * sizeof(*map->menu_info);
-		map->menu_info = kmalloc(size, GFP_KERNEL);
-		if (map->menu_info == NULL) {
-			ret = -ENOMEM;
-			goto done;
-		}
-
-		if (copy_from_user(map->menu_info, xmap->menu_info, size)) {
-			ret = -EFAULT;
+		map->menu_info = memdup_user(xmap->menu_info, size);
+		if (IS_ERR(map->menu_info)) {
+			ret = PTR_ERR(map->menu_info);
 			goto done;
 		}