The ornamental design for a cushion, as shown and described.
The file of this patent contains at least one drawing executed in color. Copies of this patent with color drawings will be provided by the Office upon request and payment of the necessary fee.
FIG. 1 is a top, front, and right side perspective view of a cushion showing our new design;
FIG. 2 is a top, rear and left side perspective view thereof;
FIG. 3 is a bottom, rear and right side perspective view thereof;
FIG. 4 is a bottom, front and left side perspective view thereof;