hv_netvsc: Register VF in netvsc_probe if NET_DEVICE_REGISTER missed

In the Linux kernel, the following vulnerability has been resolved: hv_netvsc: Register VF in netvsc_probe if NET_DEVICE_REGISTER missed If hv_netvsc driver is unloaded and reloaded, the NET_DEVICE_REGISTER handler cannot perform VF register successfully as the register call is received before netvsc_probe is finished. This is because we register register_netdevice_notifier() very early( even before vmbus_driver_register()). To fix this, we try to register each such matching VF( if it is visible as a netdevice) at the end of netvsc_probe.