The ornamental design for a self-return kiosk, as shown and described.
FIG. 1 is a perspective view of the new design taken from the front and left sides, with images appearing on a digital display portion depicted in broken lines;
FIG. 2 is a front elevation view of the design shown in FIG. 1;
FIG. 3 is a right side elevation view of the design shown in FIG. 1;
FIG. 4 is a left side elevation view of the design shown in FIG. 1;
FIG. 5 is a rear elevation view of the design shown in FIG. 1;
FIG. 6 is a top plan view of the design shown in FIG. 1; and,
FIG. 7 is a perspective view of the design shown in FIG. 1 taken from the front and top sides.
The portions depicted in broken lines form no part of the claimed design.