The ornamental design for a leg covering for a human's legs, as shown and described.
FIG. 1 is a left side elevation view of a first embodiment of the leg covering;
FIG. 2 is a front elevation view of a first embodiment of the leg covering;
FIG. 3 is a right side elevation view of a first embodiment of the leg covering; and,
FIG. 4 is a back elevation view of a first embodiment of the leg covering.
The specific patterns shown by the stippled surface shading are only representative of the two sections and the two contrasting sections and are not claimed as part of the design, and the sections of the drawing shown in phantom are not claimed as part of the design.