net/mlx5: Collect command failures data only for known commands

In the Linux kernel, the following vulnerability has been resolved:

net/mlx5: Collect command failures data only for known commands

DEVX can issue a general command, which is not used by mlx5 driver.

In case such command is failed, mlx5 is trying to collect the failure

data, However, mlx5 doesn't create a storage for this command, since

mlx5 doesn't use it. This lead to array-index-out-of-bounds error.

Fix it by checking whether the command is known before collecting the

failure data.