net: axienet: Use napi_alloc_skb when refilling RX ring

Use napi_alloc_skb to allocate memory when refilling the RX ring
in axienet_poll for more efficiency. napi_alloc_skb() can reuse
softirq-local cache of freed skbs which may still be cache-warm
and skipping allocator calls.

Signed-off-by: Robert Hancock <robert.hancock@calian.com>
Link: https://lore.kernel.org/r/20220308211013.1530955-1-robert.hancock@calian.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

drivers/net/ethernet/xilinx/xilinx_axienet_main.c

@@ -965,7 +965,7 @@ static int axienet_poll(struct napi_struct *napi, int budget)
 			packets++;
 		}
 
-		new_skb = netdev_alloc_skb_ip_align(lp->ndev, lp->max_frm_size);
+		new_skb = napi_alloc_skb(napi, lp->max_frm_size);
 		if (!new_skb)
 			break;