mwifiex: fix potential mem leak in .del_virtual_intf

1) Currently we freeing wdev for each interface in driver unload
path. We may leak memory if user have already deleted an interface.
mwifiex_add_virtual_intf() allocates wdev structure. So it should
be freed in mwifiex_del_virtual_intf().
This will make sure that wdev will be freed when user deletes an
interface and also in unload path.
2) "priv->netdev->ieee80211_ptr" should also be cleared in
mwifiex_del_virtual_intf.

Signed-off-by: Amitkumar Karwar <akarwar@marvell.com>
Signed-off-by: Bing Zhao <bzhao@marvell.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

drivers/net/wireless/mwifiex/cfg80211.c

@@ -2310,7 +2310,10 @@ int mwifiex_del_virtual_intf(struct wiphy *wiphy, struct wireless_dev *wdev)
 		unregister_netdevice(wdev->netdev);
 
 	/* Clear the priv in adapter */
+	priv->netdev->ieee80211_ptr = NULL;
 	priv->netdev = NULL;
+	kfree(wdev);
+	priv->wdev = NULL;
 
 	priv->media_connected = false;
 

drivers/net/wireless/mwifiex/main.c

@@ -998,12 +998,6 @@ int mwifiex_remove_card(struct mwifiex_adapter *adapter, struct semaphore *sem)
 	wiphy_unregister(priv->wdev->wiphy);
 	wiphy_free(priv->wdev->wiphy);
 
-	for (i = 0; i < adapter->priv_num; i++) {
-		priv = adapter->priv[i];
-		if (priv)
-			kfree(priv->wdev);
-	}
-
 	mwifiex_terminate_workqueue(adapter);
 
 	/* Unregister device */