[css-typed-om] Apply the percent hint returns a value which is never used

[AtkinsSJ]

In 3d51716987994673b9f24fbe5fa3bf94e0447781, apply the percent hint was modified, in part to add a step 4 which returns type. However, none of the callers of this algorithm make use of the return value. Can this step just be removed? It previously never returned a value.