FIG. 1 is a top perspective view of the foot buffer showing my new design; FIG. 2 is a top view of the foot buffer; FIG. 3 is a left side view of the foot buffer identical to the right side view; FIG. 4 is a bottom view of the foot buffer thereof; FIG. 5 is a front end view of the foot buffer thereof; and, FIG. 6 is a rear end view of the foot buffer thereof. The broken lines are shown for illustrative purposes only and form no part of the claimed design.