app/testpmd: fix invalid port id parameters

in parse_ringnuma_config/parse_portnuma_config functions, port_id
should be less than RTE_MAX_ETHPORTS, but port_id_is_invalid check
assumes that port_id may be RTE_PORT_ALL (65535).

Also fix port_id storage size.

Fixes: 4468635fdd04 ("app/testpmd: forbid actions on invalid port")
Cc: stable@dpdk.org
Signed-off-by: Li Han <han.li1@zte.com.cn>
Reviewed-by: Ferruh Yigit <ferruh.yigit@intel.com>