net/mlx4: Use the correct VSD mask in UPDATE_QP

When doing VGT->VST->VGT state changes, we used an incorrect mask
for the vlan-stripping-disable (VSD) flag, hence the vlan related policy
for user-space Raw Ethernet QPs open by VFs wasn't really applied.

Fix that, by using the correct mask.

Fixes: f0f829bf

 ('net/mlx4_core: Add immediate activate for VGT->VST->VGT')
Signed-off-by: Matan Barak <matanb@mellanox.com>
Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>