net: Unexport napi_gro_flush().

Nothing outside of net/core/dev.c uses it.
Signed-off-by: David S. Miller <davem@davemloft.net>

include/linux/netdevice.h

@@ -1527,7 +1527,6 @@ extern int		netif_rx(struct sk_buff *skb);
 extern int		netif_rx_ni(struct sk_buff *skb);
 #define HAVE_NETIF_RECEIVE_SKB 1
 extern int		netif_receive_skb(struct sk_buff *skb);
-extern void		napi_gro_flush(struct napi_struct *napi);
 extern gro_result_t	dev_gro_receive(struct napi_struct *napi,
 					struct sk_buff *skb);
 extern gro_result_t	napi_skb_finish(gro_result_t ret, struct sk_buff *skb);

net/core/dev.c

@@ -2582,7 +2582,7 @@ static int napi_gro_complete(struct sk_buff *skb)
 	return netif_receive_skb(skb);
 }
 
-void napi_gro_flush(struct napi_struct *napi)
+static void napi_gro_flush(struct napi_struct *napi)
 {
 	struct sk_buff *skb, *next;
 
@@ -2595,7 +2595,6 @@ void napi_gro_flush(struct napi_struct *napi)
 	napi->gro_count = 0;
 	napi->gro_list = NULL;
 }
-EXPORT_SYMBOL(napi_gro_flush);
 
 enum gro_result dev_gro_receive(struct napi_struct *napi, struct sk_buff *skb)
 {