dpaa_eth: Make dpaa_a050385_wa static

Fix sparse warning:

drivers/net/ethernet/freescale/dpaa/dpaa_eth.c:2065:5:
 warning: symbol 'dpaa_a050385_wa' was not declared. Should it be static?
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/freescale/dpaa/dpaa_eth.c

@@ -2062,7 +2062,7 @@ static inline int dpaa_xmit(struct dpaa_priv *priv,
 }
 
 #ifdef CONFIG_DPAA_ERRATUM_A050385
-int dpaa_a050385_wa(struct net_device *net_dev, struct sk_buff **s)
+static int dpaa_a050385_wa(struct net_device *net_dev, struct sk_buff **s)
 {
 	struct dpaa_priv *priv = netdev_priv(net_dev);
 	struct sk_buff *new_skb, *skb = *s;