mlxsw: spectrum: rename cls arg in matchall processing

To sync-up with the naming in the rest of the driver, rename the cls arg.

Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Acked-by: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>