net/mlx5e: Do not recover from a non-fatal syndrome

For non-fatal syndromes like LOCAL_LENGTH_ERR, recovery shouldn't be
triggered. In these scenarios, the RQ is not actually in ERR state.
This misleads the recovery flow which assumes that the RQ is really in
error state and no more completions arrive, causing crashes on bad page
state.

Fixes: 8276ea13 ("net/mlx5e: Report and recover from CQE with error on RQ")
Signed-off-by: Aya Levin <ayal@mellanox.com>
Reviewed-by: Tariq Toukan <tariqt@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>