The ornamental design for a smokedetector, as shown and described.
FIG. 1 is a perspective view of a smoke detector showing our new design
with a battery warning arm in the deployed position, with the bottom being
flat and unornamented;
FIG. 2 is a top view of the smoke detector of FIG. 1;
FIG. 3 is a side view of the smoke detector of FIG. 1 ; and,
FIG. 4 is a top view of the smoke detector of FIG. 1 with the battery
warning arm in the stored position.