We claim the ornamental design for a vent cover, as shown and described.
FIG. 1 is an exploded front view of a first embodiment of the vent cover showing the design;
FIG. 2 is a front view thereof;
FIG. 3 is an exploded rear view thereof;
FIG. 4 is a rear view thereof;
FIG. 5 is a left side view thereof, the right side view being a mirror image thereof;
FIG. 6 is an exploded right view thereof, the exploded left side view being a mirror image thereof;
FIG. 7 is a cross-sectional view thereof along line 7-7 of FIG. 2;
FIG. 8 is an exploded front view of a second embodiment of the vent cover showing the design;
FIG. 9 is a front view thereof, the left side view being identical to the view shown in FIG. 5; the right side view being a mirror image of the view shown in FIG. 5; the exploded right side view being identical to the view shown in FIG. 6; the exploded left side view being a mirror image of the view shown in FIG. 6;
FIG. 10 is an exploded rear view thereof;
FIG. 11 is a rear view thereof; and,
FIG. 12 is a cross-sectional view thereof along line 12-12 of FIG. 9.