virt_wifi: remove set but not used variable 'w_priv'

Fixes gcc '-Wunused-but-set-variable' warning:

drivers/net/wireless/virt_wifi.c: In function 'virt_wifi_net_device_stop':
drivers/net/wireless/virt_wifi.c:432:31: warning:
 variable 'w_priv' set but not used [-Wunused-but-set-variable]
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

drivers/net/wireless/virt_wifi.c

@@ -424,13 +424,11 @@ static int virt_wifi_net_device_open(struct net_device *dev)
 static int virt_wifi_net_device_stop(struct net_device *dev)
 {
 	struct virt_wifi_netdev_priv *n_priv = netdev_priv(dev);
-	struct virt_wifi_wiphy_priv *w_priv;
 
 	n_priv->is_up = false;
 
 	if (!dev->ieee80211_ptr)
 		return 0;
-	w_priv = wiphy_priv(dev->ieee80211_ptr->wiphy);
 
 	virt_wifi_cancel_scan(dev->ieee80211_ptr->wiphy);
 	virt_wifi_cancel_connect(dev);