The ornamental design for a lightfixture, as shown and described.
FIG. 1 is a perspective view showing our new design;
FIG. 2 is top plan view thereof;
FIG. 3 is a bottom plan view thereof; and,
FIG. 4 is a front elevational view thereof, the rear and side elevational views being identical.
The broken lines shown in the drawings are included for the purpose of illustrating portions of the light fixture that form no part of the claimed design.