if_usb: Kill directly reference of netdev->priv

Simply replace netdev->priv with netdev_priv().

Signed-off-by: Wang Chen <wangchen@cn.fujitsu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/wireless/libertas/if_usb.c b/drivers/net/wireless/libertas/if_usb.c
index fcd3fe6..2fc637a 100644
--- a/drivers/net/wireless/libertas/if_usb.c
+++ b/drivers/net/wireless/libertas/if_usb.c
@@ -59,7 +59,7 @@
 static ssize_t if_usb_firmware_set(struct device *dev,
 		struct device_attribute *attr, const char *buf, size_t count)
 {
-	struct lbs_private *priv = to_net_dev(dev)->priv;
+	struct lbs_private *priv = netdev_priv(to_net_dev(dev));
 	struct if_usb_card *cardp = priv->card;
 	char fwname[FIRMWARE_NAME_MAX];
 	int ret;
@@ -86,7 +86,7 @@
 static ssize_t if_usb_boot2_set(struct device *dev,
 		struct device_attribute *attr, const char *buf, size_t count)
 {
-	struct lbs_private *priv = to_net_dev(dev)->priv;
+	struct lbs_private *priv = netdev_priv(to_net_dev(dev));
 	struct if_usb_card *cardp = priv->card;
 	char fwname[FIRMWARE_NAME_MAX];
 	int ret;