net/mlx5: fix use of atomic cmpset for age state

net/mlx5: fix use of atomic cmpset for age state

According to documentation [1], function rte_atomic16_cmpset()
return value is non-zero on success; 0 on failure.
In existing code this function is called, and the return value
is compared to AGE_CANDIDATE, which is defined as 1.
Such comparison is incorrect and can lead to unwanted behavior.

This patch updates the calls to rte_atomic16_cmpset(), to check
that the return value is 0 or non-zero.

[1] https://doc.dpdk.org/api/rte__atomic_8h.html

Fixes: fa2d01c87d2b ("net/mlx5: support flow aging")
Cc: stable@dpdk.org
Signed-off-by: Dekel Peled <dekelp@nvidia.com>
Acked-by: Matan Azrad <matan@nvidia.com>