test: validation: packet: fix bugs in tailroom and concat tests
test: validation: packet: fix bugs in tailroom and concat tests

Tailroom test did not call odp_packet_extend_tail() since it pushed
tail too few bytes. Corrected the test to extend the tail by 100
bytes.

Concat test did pass the same packet as src and dst packets. There's
no valid use case to concatenate a packet into itself (forms
a loop). Corrected the test to concatenate two copies of the same
packet.

Signed-off-by: Petri Savolainen <d528fd253b9aaf78fa72edbcc6249e82047f6ce6@nokia.com>
Reviewed-and-tested-by: Bill Fischofer <52f3c909d51cc5d355a68a403df6906b3c1a8f83@linaro.org>
Signed-off-by: Maxim Uvarov <db4d16e02ae2d7493db430203537da8b2e34f290@linaro.org>

erachmi/odp,erachmi/odp,erachmi/odp,erachmi/odp