app/testpmd: fix usage text

app/testpmd: fix usage text

The options help text was including an incomplete and redundant
summary of the options before explaining each. The summary is dropped.

The details of the option --hairpin-mode had an extra space,
breaking the alignment with the next line.

There were some mismatches between options in the usage text
	sed -rn 's/.*\(" *--([a-z-]*)[=: ].*/\1/p' app/test-pmd/parameters.c
and the options declared in lgopts array
	sed -rn 's/.*\{.*"(.*)",.*,.*,.*},.*/\1/p' app/test-pmd/parameters.c
The misses were:
	--no-numa
	--enable-scatter
	--tx-ip
	--tx-udp
	--noisy-lkup-num-reads-writes
The option --ports was not implemented.

Fixes: 01817b10d27c ("app/testpmd: change hairpin queues setup")
Fixes: 3c156061b938 ("app/testpmd: add noisy neighbour forwarding mode")
Fixes: bf5b2126bf44 ("app/testpmd: add ability to set Tx IP and UDP parameters")
Fixes: 0499793854f5 ("app/testpmd: add scatter enabling option")
Fixes: 999b2ee0fe45 ("app/testpmd: enable NUMA support by default")
Fixes: af75078fece3 ("first public release")
Cc: stable@dpdk.org
Signed-off-by: Thomas Monjalon <thomas@monjalon.net>
Acked-by: Ajit Khaparde <ajit.khaparde@broadcom.com>
Acked-by: Bruce Richardson <bruce.richardson@intel.com>
Acked-by: Andrew Rybchenko <andrew.rybchenko@oktetlabs.ru>
Acked-by: Xiaoyun Li <xiaoyun.li@intel.com>
Reviewed-by: Jens Freimann <jfreimann@redhat.com>
Reviewed-by: Bing Zhao <bingz@nvidia.com>
Acked-by: David Marchand <david.marchand@redhat.com>