net/mlx5: fix shared inner RSS

net/mlx5: fix shared inner RSS

The shared RSS action use the _tunnel_ information which is derived
from flow items to decide whether need to do inner RSS or not.
However, inner RSS should be decided by RSS level (>1) in configuration
and then to create TIR with 'IBV_RX_HASH_INNER' hash bit set.

Also, for one shared RSS action there is only one set of TIRs -
outer or inner could be so the unnecessary set of TIRs are removed
in order to reduce resource.

Fixes: d2046c09aa64 ("net/mlx5: support shared action for RSS")
Cc: stable@dpdk.org
Signed-off-by: Xiaoyu Min <jackmin@nvidia.com>
Acked-by: Matan Azrad <matan@nvidia.com>