net/enic: expand local Tx mbuf flags variable to 64-bits

net/enic: expand local Tx mbuf flags variable to 64-bits

The offload flags variable (ol_flags) in rte_mbuf structure is 64-bits,
so local copy of it must be 64-bits too. Moreover bit comparison between
16-bits variable and 64-bits value make no sense. This breaks Tx vlan
IP and L4 offloads.

Coverity issue: 13218
Fixes: fefed3d1e62c ("enic: new driver")

Suggested-by: Piotr Azarewicz <piotrx.t.azarewicz@intel.com>
Signed-off-by: John Daley <johndale@cisco.com>
Acked-by: Piotr Azarewicz <piotrx.t.azarewicz@intel.com>