net/mlx5e: Fix memory leak of tunnel info when rule under multipath not ready

When deleting vxlan flow rule under multipath, tun_info in parse_attr is
not freed when the rule is not ready.

Fixes: ef06c9ee ("net/mlx5e: Allow one failure when offloading tc encap rules under multipath")
Signed-off-by: Jianbo Liu <jianbol@mellanox.com>
Reviewed-by: Roi Dayan <roid@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>