net: veth: rely on napi_build_skb in veth_convert_skb_to_xdp_buff

Since veth_convert_skb_to_xdp_buff routine runs in veth_poll() NAPI,
rely on napi_build_skb() instead of build_skb() to reduce skb allocation
cost.

Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
Reviewed-by: Yunsheng Lin <linyunsheng@huawei.com>
Link: https://lore.kernel.org/r/0f822c0b72f8b71555c11745cb8fb33399d02de9.1683578488.git.lorenzo@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Author: LorenzoBianconi

drivers/net/veth.c

@@ -747,7 +747,7 @@ static int veth_convert_skb_to_xdp_buff(struct veth_rq *rq,
 		if (!page)
 			goto drop;
 
-		nskb = build_skb(page_address(page), PAGE_SIZE);
+		nskb = napi_build_skb(page_address(page), PAGE_SIZE);
 		if (!nskb) {
 			page_pool_put_full_page(rq->page_pool, page, true);
 			goto drop;