datapath-windows: cleanup AssignNicNameSpecial()

datapath-windows: cleanup AssignNicNameSpecial()

AssignNicNameSpecial() needed to be called outside of a lock and was
moved out in a previous change. But, it was accessing vport structure
outside of the lock which isn't safe. In this change, we take care of
that.

I tried to trigger a call to HvUpdateNic() by renaming the interface
from the GUI and didn't see any callback. Other changes are tested.

Signed-off-by: Nithin Raju <nithin@vmware.com>
Acked-by: Sairam Venugopal <vsairam@vmware.com>
Acked-by: Alin Gabriel Serdean <aserdean@cloudbasesolutions.com>
Signed-off-by: Gurucharan Shetty <guru@ovn.org>