Since previous commit, the flag PKT_TX_UDP_TUNNEL_PKT is not used by any PMD,
remove it from mbuf API and from csumonly (testpmd). In csumonly, the
PKT_TX_OUTER_IP_CKSUM flag is already set for vxlan checksum, providing
enough information to the underlying driver.
Signed-off-by: Olivier Matz <olivier.matz@6wind.com>
Acked-by: Jijiang Liu <jijiang.liu@intel.com>