The ornamental design for a pole, as shown and described.
FIG. 1 is a front perspective view of a pole.
FIG. 2 is a right side elevation view of the pole of FIG. 1, it being understood that the left side elevation view is identical to the right side elevation view.
FIG. 3 is a front elevation view of the pole of FIG. 1; and,
FIG. 4 is a back elevation view of the pole of FIG. 1.
Portions or features of the pole not shown in the drawings form no part of the claimed design. The broken lines in the drawings form no part of the claimed design.