The ornamental design for a cover for glassware, as shown and described.
FIG. 1 is an isometric view of a cover for glassware showing my new design;
FIG. 2 is an isometric view in use thereof;
FIG. 3 is a left side view, the right side view being a mirror image thereof;
FIG. 4 is a front view, the rear view being a mirror image thereof;
FIG. 5 is a top view thereof; and,
FIG. 6 is a bottom view thereof.
The broken lines in FIG. 2 depict environmental structure that forms no part of the claimed design. The broken lines and areas within them in FIG. 6 depict portions of the cover for glasswear that form no part of the claimed design.