The ornamental design for a wadersock, as shown and described.
FIG. 1 is a perspective view of a wader sock showing my new design;
FIG. 2 is a front view thereof;
FIG. 3 is a rear view thereof;
FIG. 4 is a right side view thereof;
FIG. 5 is a left side view thereof;
FIG. 6 is a top view thereof; and,
FIG. 7 is a bottom view thereof.
The broken lines shown on the cuff of the sock represent thread stitching. The broken lines illustrating the circles on the sole and heel of the sock form no part of the claimed design.