I claim the ornamental design for a pocket, as shown and described.
FIG. 1 is a front perspective view of a pocket showing my new design.
FIG. 2 is a front view of the invention;
FIG. 3 is a left side view of the invention;
FIG. 4 is a right side view of the invention;
FIG. 5 is a top view of the invention; and,
FIG. 6 is a bottom view of the invention.
The broken lines shown on the surface of the pocket in FIGS. 1 and 2 represent stitching.
The broken lines shown surrounding the pocket in FIG. 1 represent an article of clothing on which the pocket is attached, and forms no part of the claimed design.