The ornamental design for a changing padcover, as shown and described.
FIG. 1 is a perspective view of a changing pad cover showing our new design;
FIG. 2 is a front view thereof, the back view being identical;
FIG. 3 is a right side view thereof, the left side view being identical;
FIG. 4 is a top view thereof; and,
FIG. 5 is a bottom view thereof.
The broken lines illustrating portions of the changing pad cover form no part of the claimed design. The surface of the interior panel of material has a smooth, wipeable surface as depicted by the stipple shading. The surfaces of the exterior panels of material have a plush surface as depicted by the cross-hatch shading.