We claim the ornamental design for an electronic device, as shown and described.
FIG. 1 is the front perspective view of an electronic device showing our new design;
FIG. 2 is the front view thereof;
FIG. 3 is the rear view thereof;
FIG. 4 is the left-side view thereof;
FIG. 5 is the right-side view thereof;
FIG. 6 is the top view thereof;
FIG. 7 is the bottom view thereof;
FIG. 8 is the rear perspective view thereof; and,
FIG. 9 is the partially enlarged view of the encircled portion in FIG. 1.
The broken lines in the figures depict environmental subject matter and form no part of the claimed design. The dot-dash lines in the figures represent an unclaimed boundary line and form no part of the claimed design. The dot-dot-dash broken lines encircling portions of the claimed design that are illustrated in enlargements form no part of the claimed design.