The ornamental design of a lightingfixture, as shown and described.
FIG. 1 is a front perspective view of a lighting fixture in accordance with a first embodiment of the present invention;
FIG. 2 is a front view thereof;
FIG. 3 is a right side view thereof;
FIG. 4 is a rear view thereof;
FIG. 5 is a left side view thereof;
FIG. 6 is a top view thereof; and,
FIG. 7 is a bottom view thereof.
The lighting fixture is not limited to the scale shown herein. The broken lines of the Figures are for illustrative purposes only and form no part of the claimed design.