netdev-windows: fix ofpbuf initialization

netdev-windows: fix ofpbuf initialization

ofpbuf_const_initializer takes only two parameters see:

https://github.com/openvswitch/ovs/blob/master/include/openvswitch/ofpbuf.h#L96

the compiler only gives the following warning:

lib/netdev-windows.c(229) : warning C4020: 'ofpbuf_const_initializer' :
too many actual parameters

which in result will put junk data into "ofpbuf b".

This patch fixes the initialization.

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