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, illustrating movable portions;
FIG. 2 is a front elevation view of the light fixture in accordance with my design, illustrating movable portions, the opposite view being a mirror image of that shown, except for the positioning of the movable portion;
FIG. 3 is a bottom plan view of the light fixture in accordance with my design, illustrating movable portions; and,
FIG. 4 is a side elevation view of the light fixture in accordance with my design, illustrating movable portions, the opposite view being a mirror image of that shown.