net/mlx5: fix default queue number in RSS flow rule

net/mlx5: fix default queue number in RSS flow rule

The selection flags for the RX hash define how the received packets will
be distributed between multiple queues.
When creating a new TIR, the queue_num is set to 1 if none of the selection
flags is set.

Applied the same to the RSS desc before checking if it matches a cached
TIR object to save creating a new object every time.

Fixes: fabf8a37241c ("net/mlx5: fix shared RSS action release")
Cc: stable@dpdk.org
Signed-off-by: Lior Margalit <lmargalit@nvidia.com>
Acked-by: Matan Azrad <matan@nvidia.com>