net: use napi_consume_skb() in skb_defer_free_flush()

skb_defer_free_flush() runs from softirq context,
we have the opportunity to refill the napi_alloc_cache,
and/or use kmem_cache_free_bulk() when this cache is full.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/core/dev.c

@@ -6633,7 +6633,7 @@ static void skb_defer_free_flush(struct softnet_data *sd)
 
 	while (skb != NULL) {
 		next = skb->next;
-		__kfree_skb(skb);
+		napi_consume_skb(skb, 1);
 		skb = next;
 	}
 }