ethdev: fix shallow copy of flow API RAW item

ethdev: fix shallow copy of flow API RAW item

Like original commit mentioned below, this fix synchronizes flow rule copy
function with testpmd's own implementation following "app/testpmd: fix copy
of raw flow item (revisited)".

It addresses a crash that occurs when feeding a RAW pattern item to
rte_flow_copy(). Besides external applications, two PMDs (bonding and
failsafe) rely on this function internally.

Note the scope of this patch is limited to the RAW pattern item and has no
impact on all others.

Fixes: 972bf3610611 ("ethdev: fix shallow copy of flow API RSS action")
Cc: stable@dpdk.org
Signed-off-by: Adrien Mazarguil <adrien.mazarguil@6wind.com>