The ornamental design for a wallstorageunit, as shown and described.
FIG. 1 is a top, front, and right side perspective view of a wall storage unit showing my new design;
FIG. 2 is an enlarged front elevational view thereof;
FIG. 3 is an enlarged right side elevational view thereof;
FIG. 4 is an enlarged top plan view thereof; and,
FIG. 5 is an enlarged bottom plan view thereof.
The broken-line disclosure of two additional units, scarf, mobile telephone, hat, and light switch are shown for illustrative purposed only and form no part of the claimed design. The broken-line disclosure on the unit itself are understood to represent an unclaimed boundary between claimed and unclaimed portions of the article in which the claimed design is embodied, the claimed portions being shown with surface shading.