igbvf: fix vlan filtering
igbvf: fix vlan filtering

Once posted through mailbox, we must check for nack from the PF
and report an error in this case.

Signed-off-by: Julien Meunier <0f47299d6d7be29de9aa672c2fd4f9e07862696a@6wind.com>
Signed-off-by: David Marchand <f28529695cfa9e3e1eb84e7072aa626af4abb18e@6wind.com>
Acked-by: Wenzhuo Lu <58cb9036bdff9a5412edc3b9f70e105ccf59954f@intel.com>

john-mcnamara-intel/dpdk,john-mcnamara-intel/dpdk,john-mcnamara-intel/dpdk,john-mcnamara-intel/dpdk