The ornamental design for a storagerack, as shown and described.
FIG. 1 is a top, front, left perspective view of a storage rack showing our new design;
FIG. 2 is a top, rear, left perspective view thereof;
FIG. 3 is a top view thereof;
FIG. 4 is a bottom view thereof;
FIG. 5 is a front view thereof;
FIG. 6 is a rear view thereof;
FIG. 7 is a right side view thereof; and,
FIG. 8 is a left side view thereof.
The uneven-length broken lines immediately adjacent to the shaded areas define the bounds of the claimed design and form no part thereof. The even-length broken lines depicting the remainder of the storage rack show portions forming no part of the claimed design.