The ornamental design for the massaging device, as shown and described.
FIG. 1 is a front view of the massaging device.
FIG. 2 is a rear view of the claimed design.
FIG. 3 is a left side view of the claimed design.
FIG. 4 is a top view of the claimed design with the logo “ShaHia” in hidden lines, which is environmental matter and does not form a part of the claimed design.
FIG. 5 is a bottom view of the claimed design; and,
FIG. 6 is an isometric view of the claimed design with the logo “ShaHia” in hidden lines, which is environmental matter and does not form a part of the claimed design.