The ornamental design for a pocket, as shown and described.
FIG. 1 is a front elevational view of a pocket showing my new design.
FIG. 2 is another front elevational view thereof.
FIG. 3 is a perspective view thereof.
FIG. 4 is another front elevational view thereof.
FIG. 5 is another perspective view thereof.
FIG. 6 is a left side elevational view thereof.
FIG. 7 is another front elevational view thereof.
FIG. 8 is a right side elevational view thereof.
FIG. 9 is a top view thereof.
FIG. 10 is a bottom view thereof; and,
FIG. 11 is yet another perspective view thereof.
The line shadings in the figures are included for the purpose of illustrating contour and are not intended to be illustrative of texture or gloss. None of the broken lines form a part of the claimed design.