The ornamental design for a lightfixture, as shown and described.
FIG. 1 is a perspective view of a light fixture showing our new design;
FIG. 2 is a first side elevational view thereof;
FIG. 3 is a second side elevational view thereof;
FIG. 4 is a third side elevational view thereof;
FIG. 5 is a fourth side elevational view thereof;
FIG. 6 is a top plan view thereof; and,
FIG. 7 is a bottom plan view thereof.
The broken lines shown in the drawings are included for the purpose of illustrating elements of the light fixture that is surface mountable and form no part of the claimed design.