The ornamental design for a penclip, as shown and described.
FIG. 1 is a front side bottom perspective view of a pen clip showing my new design;
FIG. 2 is a front elevational view thereof;
FIG. 3 is a right side elevational view thereof which is a mirror image of the left side thereof;
FIG. 4 is a back elevational view thereof;
FIG. 5 is a bottom plan view thereof; and,
FIG. 6 is a top plan view thereof.
The broken lines showing the pen body and inside of the collar are included for the purpose of illustrating environmental structure forming no part of the claimed design.