In the Testpmd Flow rules management section, correct
the TPID values in the Sample QinQ flow rules sub section.
Also replace the keyword qinq_strip with extend in the
vlan set command.
Fixes: bef3bfe7d5f4 ("doc: revise sample testpmd flow commands")
Cc: stable@dpdk.org
Signed-off-by: Bernard Iremonger <bernard.iremonger@intel.com>
Acked-by: Xiaoyun Li <xiaoyun.li@intel.com>