The ornamental design for a lightfixture, as shown and described.
FIG. 1 is a perspective view of a light fixture in accordance with my design;
FIG. 2 is a top plan view of the light fixture in accordance with my design;
FIG. 3 is a bottom plan view of the light fixture in accordance with my design;
FIG. 4 is a front elevation view of the light fixture in accordance with my design, the opposite view being a mirror image of that shown; and,
FIG. 5 is a side elevation view of the light fixture in accordance with my design, the opposite view being a mirror image of that shown.
The broken-line disclosure of elements is understood to represent portions of the article in which the design is embodied, but which form no part of the claimed design.