ixgbe: Fix SR-IOV VLAN pool configuration

The code for checking the PF bit in ixgbe_set_vf_vlan_msg was using the
wrong offset and as a result it was pulling the VLAN off of the PF even if
there were VFs numbered greater than 40 that still had the VLAN enabled.

Signed-off-by: Alexander Duyck <aduyck@mirantis.com>
Tested-by: Phil Schmitt <phillip.j.schmitt@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>