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.

Fixes: 34f46ae ("net/mlx5: Add command failures data to debugfs")
Signed-off-by: Shay Drory <shayd@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>

drivers/net/ethernet/mellanox/mlx5/core/cmd.c

@@ -1920,9 +1920,10 @@ static void mlx5_cmd_err_trace(struct mlx5_core_dev *dev, u16 opcode, u16 op_mod
 static void cmd_status_log(struct mlx5_core_dev *dev, u16 opcode, u8 status,
 			   u32 syndrome, int err)
 {
+	const char *namep = mlx5_command_str(opcode);
 	struct mlx5_cmd_stats *stats;
 
-	if (!err)
+	if (!err || !(strcmp(namep, "unknown command opcode")))
 		return;
 
 	stats = &dev->cmd.stats[opcode];