The ornamental design for a pencilsharpener, as shown and described.
FIG. 1 is a perspective view of the pencil sharpener;
FIG. 2 is a perspective view thereof from the opposite side;
FIG. 3 is a front view thereof;
FIG. 4 is a rear view thereof;
FIG. 5 is a right side view thereof;
FIG. 6 is a left side view thereof;
FIG. 7 is a top plan view thereof; and,
FIG. 8 is a bottom plan view thereof.
The broken lines showing the pencil, the power cord, the bottom surface including feet and the features inside are included to show features that form no part of the claimed design.