FIG. 1 is a perspective view of the lighting fixture showing my new design; FIG. 2 is a front elevational view of the lighting fixture, the rear elevational view being identical; FIG. 3 is a right side elevational view of the lighting fixture, the left side elevational view being identical, FIG. 4 is a top plan view of the lighting fixture; FIG. 5 is a bottom plan view of the lighting fixture; FIG. 6 is a perspective view of the second embodiment of the lighting fixture showing my new design; FIG. 7 is a front elevational view of the second embodiment of the lighting fixture, the rear elevational view being identical; FIG. 8 is a right side elevational view of the second embodiment of the lighting fixture, the left side elevational view being identical; FIG. 9 is a top plan view of the second embodiment of the lighting fixture; and, FIG. 10 is a bottom plan view of the second embodiment of the lighting fixture. The broken lines shown are for illustrative purposes only and form no part of the claimed design.