staging: vt6656: use free_netdev instead of kfree

use free_netdev() instead of kfree(pDevice->apdev)

Signed-off-by: Hema Prathaban <[e-mail]>
Cc: stable <[e-mail]>
Signed-off-by: Greg Kroah-Hartman <[e-mail]>

drivers/staging/vt6656/hostap.c

···
             DBG_PRT(MSG_LEVEL_DEBUG, KERN_INFO "%s: Netdevice %s unregistered\n",
 		       pDevice->dev->name, pDevice->apdev->name);
 	}
-	kfree(pDevice->apdev);
+	free_netdev(pDevice->apdev);
 	pDevice->apdev = NULL;
     pDevice->bEnable8021x = false;
     pDevice->bEnableHostWEP = false;