app/testpmd: report invalid command line parameter

app/testpmd: report invalid command line parameter

We currently do not check that a non option string has been passed to
testpmd.

Example:
$ ./master/app/testpmd --no-huge -m 512 --vdev net_null0 \
	--vdev net_null1 -- -i nb-cores=2 --total-num-mbuf 2048
[...]
testpmd> show config fwd
io packet forwarding - ports=2 - cores=1 - streams=2 - NUMA support
enabled, MP allocation mode: native
Logical Core 1 (socket 0) forwards packets on 2 streams:
  RX P=0/Q=0 (socket 0) -> TX P=1/Q=0 (socket 0) peer=02:00:00:00:00:01
  RX P=1/Q=0 (socket 0) -> TX P=0/Q=0 (socket 0) peer=02:00:00:00:00:00

Here nb-cores=2 is just ignored, while the (probably sleepy) user did not
notice this.

Validate that all strings passed to testpmd are part of a known option.

After this patch:
$ ./master/app/testpmd --no-huge -m 512 --vdev net_null0 \
	--vdev net_null1 -- -i nb-cores=2 --total-num-mbuf 2048
[...]
Invalid parameter: nb-cores=2
EAL: Error - exiting with code: 1
  Cause: Command line incorrect

While at it, when passing an unknown option, print the string that gets
refused by getopt_long to help the user.

Fixes: af75078fece3 ("first public release")
Cc: stable@dpdk.org
Signed-off-by: David Marchand <david.marchand@redhat.com>
Reviewed-by: Ferruh Yigit <ferruh.yigit@intel.com>