app/testpmd: fix csum parse-tunnel command invocation
app/testpmd: fix csum parse-tunnel command invocation

Based on the documentation and help print, the sub command
for csum suppose to be "parse-tunnel" instead of "parse_tunnel".

Fixes: 64fc36064dc3 ("app/testpmd: add csum parse-tunnel command")
Cc: stable@dpdk.org

Signed-off-by: Jerin Jacob <5bca7d2a432bc0f5422b70b2701a4e4fa32edd00@caviumnetworks.com>
Acked-by: Bernard Iremonger <233eeff376ad0c06f66f06c5522ea3c4feb30d3b@intel.com>

john-mcnamara-intel/dpdk,john-mcnamara-intel/dpdk,john-mcnamara-intel/dpdk,john-mcnamara-intel/dpdk