The ornamental design for a lightfixture, as shown and described.
FIG. 1 is a top perspective view of a light fixture.
FIG. 2 is a front elevation view of the light fixture of FIG. 1, it being understood that the rear elevation view is identical to the front elevation view.
FIG. 3 is a right side elevation view of the light fixture of FIG. 1, it being understood that the left side elevation view is identical to the right side elevation view.
FIG. 4 is a top plan view of the light fixture of FIG. 1; and,
FIG. 5 is a bottom plan view of the light fixture of FIG. 1.
Portions or features of the light fixture not shown in the drawings form no part of the claimed design. The evenly dotted broken lines in the drawings represent borders of unclaimed portions of the design and form no part of the claimed design.