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 side elevation view of the light fixture in accordance with my design, the other side views being substantially identical thereto;
FIG. 3 is a top plan view of the light fixture in accordance with my design; and,
FIG. 4 is a bottom plan view of the light fixture in accordance with my design.
The portions of the light fixture shown broken away in FIGS. 1-2 are to depict nonspecific 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.