The ornamental design for a foot covering, as shown and described.
FIG. 1 is a bottom perspective view of a foot covering showing the design;
FIG. 2 is a top plan view of the foot covering of FIG. 1;
FIG. 3 is a bottom plan view of the foot covering of FIG. 1;
FIG. 4 is a front elevational view of the foot covering of FIG. 1;
FIG. 5 is a rear elevational view of the foot covering of FIG. 1;
FIG. 6 is a left elevational view of the foot covering of FIG. 1; and,
FIG. 7 is a right elevational view of the foot covering of FIG. 1.
Dash-dash broken lines showing environment in the drawings are included for illustrative purposes only and form no part of the claimed design. Dash-dot-dash broken lines shown in the drawings define the boundaries of the claim and form no part thereof.