The ornamental design for a potatopiece, as shown.
FIG. 1 is a perspective view of a potato piece embodying the new design;
FIG. 2 is a front elevational view thereof;
FIG. 3 is a rear elevational view thereof;
FIG. 4 is a right side elevational view thereof;
FIG. 5 is a left side elevational view thereof;
FIG. 6 is a top plan view thereof; and,
FIG. 7 is a bottom plan view thereof.
The evenly-spaced broken lines in FIGS. 1-7 illustrate end portions of the potato piece that form no part of the claimed design. The dash-dot-dash broken lines in FIGS. 1 and 4-7 illustrate the boundary of the claimed design which forms no part thereof.