The ornamental design for a lightingfixture, as shown and described.
FIG. 1 is a bottom-side perspective view of the design of the present disclosure;
FIG. 2 is a left-side view of the design of FIG. 1, the right-side view, front view and rear view being the same;
FIG. 3 is a bottom view of the design of FIG. 1; and,
FIG. 4 is a top view of the design of FIG. 1.
Those portions of the present invention which are presented in phantom illustrate the environment of the design only and form no part of the claimed design. Moreover, any shading presented in the accompanying drawings is provided merely to highlight the contour of the invention and is not intended to be illustrative of texture or gloss.