The ornamental design for a lightingfixture, as shown and described.
FIG. 1 is a front view of the lighting fixture, with the rear view being a
mirror image of the front view;
FIG. 2 is a top view of the lighting fixture;
FIG. 3 is a bottom view of the lighting fixture; and,
FIG. 4 is a side view of the lighting fixture.
The broken lines showing the glass lampshade is for illustrative purposes
only and forms no part of the claimed design. The stippling is for shading
purposes only, and forms no part of the claimed invention.