Fix sriov trunk creation with subports
Fix sriov trunk creation with subports

When creating trunk with multiple subports,
driver erroneously assumed that update of some
of the trunk subports failed, and threfor did set
trunk state to DEGRADED.

Change-Id: Ifbae4bd936a6937c098362a7393749d1192afcc1
Closes-Bug: OPENSTACK-2108
Closes-Bug: OPENSTACK-2109

nuagenetworks/nuage-openstack-neutron,nuagenetworks/nuage-openstack-neutron