i40e: Fix VF VLAN offloading when port VLAN is configured

JIRA: https://issues.redhat.com/browse/RHEL-6382
Tested: Manually on i40e

Commits:

d0d362ffa33d ("i40e: Fix VF VLAN offloading when port VLAN is configured")

Signed-off-by: Ivan Vecera ivecera@redhat.com