The ornamental design for a wall covering, as shown and described.
The single FIGURE is a top view of a wall covering showing my new design.
The bottom surface of the wall covering is plain and unornamented, and the
sides have no substantial thickness. The inner dash-dot broken lines
depict the boundaries of one repeat unit of the printed indicia, which
repeats with uniform spacing throughout the width of the wall covering,
and the outer broken line boundary indicates that the wall covering has
indeterminate length and width. It is understood that each band of indicia
showing the words "Harley Davidson" repeats uniformly throughout the
entire length of the wall covering.