net/mlx5: fix GRE item translation in Verbs

net/mlx5: fix GRE item translation in Verbs

GRE item translation must set inner protocol value.
For that reason the item is not translated inplace when PMD
translation iterates over flow items, but moved after the loop, when
all inner types are discovered.

If PMD does not translate GRE flow item inside the translation loop
it must save the GRE item for access outside the loop.

Fixes: 985b479267aa ("net/mlx5: fix GRE protocol type translation for Verbs")
Cc: stable@dpdk.org
Signed-off-by: Gregory Etelson <getelson@nvidia.com>
Acked-by: Viacheslav Ovsiienko <viacheslavo@nvidia.com>