We claim the ornamental design for a lighting fixture, as shown and described.
FIG. 1 is a perspective view of the claimed design;
FIG. 2 is a front view of the claimed design shown in FIG. 1;
FIG. 3 is a rear view of the claimed design shown in FIG. 1;
FIG. 4 is a top view of the claimed design shown in FIG. 1;
FIG. 5 is a bottom view of the claimed design shown in FIG. 1;
FIG. 6 is a side view of the claimed design shown in FIG. 1; and,
FIG. 7 is another side view of the claimed design shown in FIG. 1.
The ornamental design that is claimed is shown in the drawings as solid lines and surfaces having surface shading. The broken lines shown on the drawings depict portions of the lighting fixture that form no part of the claimed design.