Read that IFRS 1.11 goes like this "The accounting policies that an entity uses in its opening IFRS statement of financial position may differ from those that it used for the same date using its previous GAAP. The resulting adjustments arise from events and transactions before the date of transition to IFRSs. Therefore, an entity shall recognise those adjustments directly in retained earnings (or, if appropriate, another category of equity) at the date of transition to IFRSs."
So it is clear that you should use retained earnings for adjustments for previous years.