net/mlx5: fix flow tables double release

net/mlx5: fix flow tables double release

In the function mlx5_alloc_shared_dr(), there are various reasons
to result in a failure and error clean up process. While in the
caller of mlx5_dev_spawn(), once there is a error occurring after
the mlx5_alloc_shared_dr(), the mlx5_os_free_shared_dr() is called
to release all the resources.

To prevent a double release, the pointers of the resources should
be checked before the releasing and set to NULL after done.

In the mlx5_free_table_hash_list(), after the releasing, the pointer
was missed to set to NULL and a double release may cause a crash.

By setting the tables pointer to NULL as done for other resources,
the double release and crash could be solved.

Fixes: 54534725d2f3 ("net/mlx5: fix flow table hash list conversion")
Cc: stable@dpdk.org
Signed-off-by: Bing Zhao <bingz@nvidia.com>
Acked-by: Matan Azrad <matan@nvidia.com>