Intermittent wrong ol_flag in rte_mbuf when vlan offload strip is used

Issue

• Intermittent wrong ol_flag in rte_mbuf when vlan offload strip is used.
• vdev virtio_user0 is used and tap0 is created automatically inside the dpdk Pod. On top of tap0 a vlan and IP will be configured and the tap0 will send ARP broadcast to get MAC address for a range of subnets.
• When the ARP reply is sent back to VF, the ol_flag is lacking two bits intermittently. This will cause the packet be sent to the wrong interface and cause retransmit of ARP broadcast. This could cause packet drop.
• To be more specific the following two bits are missing in the ol_flag.

 #define RTE_MBUF_F_RX_VLAN          (1ULL << 0)
 #define RTE_MBUF_F_RX_VLAN_STRIPPED (1ULL << 6)

• Correct ol_flag:

_iavf_recv_raw_pkts_vec_avx2_flex_rxd(): arp: pktlen:60, vlan_tci:58160, ol_flag:449

>>> bin(449)
'0b111000001'

• Wrong ol_flag:

_iavf_recv_raw_pkts_vec_avx2_flex_rxd(): arp: pktlen:60, vlan_tci:58160, ol_flag:384

>>> bin(384)
'0b110000000'