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 left-side elevation view of the light fixture in accordance with my design;
FIG. 3 is a right-side view of the light fixture in accordance with my design;
FIG. 4 is a bottom plan view of the light fixture in accordance with my design; and,
FIG. 5 is a front elevation view of the light fixture in accordance with my design.
The portions of the light fixture shown broken away in FIGS. 1 and 4-5 are to depict non-specific length.
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.