Fixed some ineffective assignments (#12543)

model/link_metadata.go

@@ -56,9 +56,7 @@ func firstNImages(images []*opengraph.Image, maxImages int) []*opengraph.Image {
 	}
 	numImages := len(images)
 	if numImages > maxImages {
-		subImages := make([]*opengraph.Image, maxImages)
-		subImages = images[0:maxImages]
-		return subImages
+		return images[0:maxImages]
 	}
 	return images
 }