We claim the ornamental design for an incense burner, as shown and described.
FIG. 1 is a perspective view of an incense burner;
FIG. 2 is a front view of the incense burner of FIG. 1;
FIG. 3 is a rear view of the incense burner of FIG. 1;
FIG. 4 is a side view of the incense burner of FIG. 1;
FIG. 5 is a side view of the incense burner of FIG. 1;
FIG. 6 is a top side view of the incense burner of FIG. 1; and,
FIG. 7 is a bottom side view of the incense burner of FIG. 1.
In the drawings, the broken lines depict environmental subject matter only and form no part of the claimed design. The incense burner is shown with a symbolic break in its length, with dash/dot/dot/dash lines indicating boundaries of the claim. The appearance of any portion of the article between the break lines forms no part of the claimed design.