net/mlx5: Avoid report two health errors on same syndrome

In case health counter has not increased for few polling intervals, miss
counter will reach max misses threshold and health report will be
triggered for FW health reporter. In case syndrome found on same health
poll another health report will be triggered.

Avoid two health reports on same syndrome by marking this syndrome as
already known.

Signed-off-by: Moshe Shemesh <moshe@nvidia.com>
Reviewed-by: Shahar Shitrit <shshitrit@nvidia.com>
Signed-off-by: Tariq Toukan <tariqt@nvidia.com>
Reviewed-by: Kalesh AP <kalesh-anakkur.purayil@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>