The ornamental design for a dockfender, as shown and described.
FIG. 1 is a front perspective view of a dock fender of the present invention;
FIG. 2 is a bottom view of the dock fender of FIG. 1. The top view of the dock fender is a mirror image of the bottom view of the dock fender of FIG. 1;
FIG. 3 is a front view of the dock fender of FIG. 1;
FIG. 4 is a side view of the dock fender of FIG. 1; and,
FIG. 5 is a rear view of the dock fender of FIG. 1.