app/testpmd: fix physical port socket initialization

Once the lcore list setting excluded the socket which physical device
attached, it will cause failure. Meanwhile, it will disable Testpmd
cross NUMA scenario.

Fixes: dbfb8ec7094c ("app/testpmd: optimize mbuf pool allocation")
Cc: stable@dpdk.org
Signed-off-by: Phil Yang <phil.yang@arm.com>
Reviewed-by: Gavin Hu <gavin.hu@arm.com>
Acked-by: Konstantin Ananyev <konstantin.ananyev@intel.com>