Mortgage Servicing Clarification Act - Amends the Fair Debt Collection Practices Act to exempt from mandatory debt collection disclosures (that the debt collector is attempting to collect a debt and any information obtained will be used for that purpose) any servicer of federally related mortgage loans secured by first liens that include loans in default at the time such servicer became responsbile for servicing such loans, if the servicer is also a debt collector whose collections are incidental to a primary function of servicing current federally related-mortgage loans.