The ornamental design for a lightingfixture, as shown and described.
1. Lighting fixture
Fig. 1.1 is a perspective view;
Fig. 1.2 is a left side elevation view;
Fig. 1.3 is a right side elevation view;
Fig. 1.4 is a front elevation view;
Fig. 1.5 is a rear elevation view;
Fig. 1.6 is a bottom plan view;
Fig. 1.7 is a top plan view.
The dash-dot-dash broken lines shown represent the bounds of the claim and forms no part thereof and the dashed broken lines shown therein illustrate portions of the luminaire that form no part of the claimed design.