I claim the ornamental design for a cushioning device, as shown and described.
FIG. 1 is a frontal perspective view of a cushioning device according to my design;
FIG. 2 is a front view of the cushioning device shown in FIG. 1;
FIG. 3 is a back view of the cushioning device shown in FIG. 1;
FIG. 4 is a left side view of the cushioning device shown in FIG. 1;
FIG. 5 is a right view of the cushioning device shown in FIG. 1;
FIG. 6 is a top view of the cushioning device shown in FIG. 1; and,
FIG. 7 is a bottom view of the cushioning device shown in FIG. 1.
The ornamental design which is claimed is shown in solid lines in the drawings. The broken lines in the drawings are for illustrative purposes only and form no part of the claimed design.