The ornamental design for a barrette, as shown and described.
FIG. 1 is a side elevational view of the barrette showing my new design. The broken lines in the drawing are for illustrative purposes only and form no part of the claimed design;
FIG. 2 is a front elevational view;
FIG. 3 is a perspective view; and,
FIG. 4 is a top plan view.
The bottom portion of the barrette does not form part of the claim.