mlxsw: spectrum_qdisc: Simplify mlxsw_sp_qdisc_compare()

mlxsw: spectrum_qdisc: Simplify mlxsw_sp_qdisc_compare()

The purpose of this function is to filter out events that are related to
qdiscs that are not offloaded, or are not offloaded anymore. But the
function is unnecessarily thorough:

- mlxsw_sp_qdisc pointer is never NULL in the context where it is called
- Two qdiscs with the same handle will never have different types. Even
  when replacing one qdisc with another in the same class, Linux will not
  permit handle reuse unless the qdisc type also matches.

Simplify the function by omitting these two unnecessary conditions.

Signed-off-by: Petr Machata <petrm@nvidia.com>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>