The ornamental design for a hinge cover, as shown and described.
FIG. 1 is a top-front perspective view of a hinge cover according to a first embodiment of our design;
FIG. 2 is a top view thereof;
FIG. 3 is a bottom view thereof;
FIG. 4 is a left-side elevation view thereof;
FIG. 5 is a right-side elevation view thereof; and,
FIG. 6 is a front elevation view thereof.
The broken lines are of portions of the hinge cover that form no part of the claimed design. The dash-dot lines adjacent un-shaded areas represent bounds of the claimed design and form no part of the claimed design themselves.