datapath-windows: Rename OvsFlowNlNewCmdHandler to OvsFlowNlCmdHandler

datapath-windows: Rename OvsFlowNlNewCmdHandler to OvsFlowNlCmdHandler

OvsFlowNlNewCmdHandler NEW/DEL/SET/FLUSH commands hence renaming it to
OvsFlowNlCmdHandler.

Signed-off-by: Ankur Sharma <ankursharma@vmware.com>
Acked-by: Alin Gabriel Serdean <aserdean@cloudbasesolutions.com>
Acked-by: Eitan Eliahu <eliahue@vmware.com>
Acked-by: Nithin Raju <nithin@vmware.com>
Acked-by: Samuel Ghinet <sghinet@cloudbasesolutions.com>
Tested-by: Ankur Sharma <ankursharma@vmware.com>
Signed-off-by: Ben Pfaff <blp@nicira.com>