End Unnecessary Borrowing Act of 2017 This bill amends the National Housing Act with respect to the requirement that the Department of Housing and Urban Development (HUD) endeavor to ensure that the Mutual Mortgage Insurance Fund (MMI Fund) attains a capital ratio of not less than 2% within 10 years after enactment of that requirement (November 5, 1990) and to ensure that the fund maintains at least that capital ratio at all times thereafter. The bill prohibits these requirements from being construed to authorize or require HUD to borrow any amounts to comply with the capital ratio requirement. Any HUD authority to borrow from the Treasury for the MMI Fund may be used only to the extent necessary to pay claims on mortgage insurance that is an obligation of such fund.