net/mlx5: DR, Fix memory leak during rule creation

During rule creation hw_ste_arr was not freed.

Fixes: 41d07074 ("net/mlx5: DR, Expose steering rule functionality")
Signed-off-by: Alex Vesker <valex@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>