net/i40e: fix data path selection in secondary process

net/i40e: fix data path selection in secondary process

The flag use_avx2 and use_avx512 are defined as local variables, they
will not be aware by the secondary process, then wrong data path is
selected. Fix the issue by moving them into struct i40e_adapter.

Fixes: 6ada10deac66 ("net/i40e: remove devarg use-latest-supported-vec")
Fixes: e6a6a138919f ("net/i40e: add AVX512 vector path")
Cc: stable@dpdk.org
Signed-off-by: Dapeng Yu <dapengx.yu@intel.com>
Acked-by: Qi Zhang <qi.z.zhang@intel.com>