hv_netvsc: pass struct net_device to rndis_filter_set_offload_params()

The only caller rndis_filter_device_add() has 'struct net_device' pointer
already.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>