The ornamental design for the lighting fixture, as shown and described.
FIG. 1 is a front elevation view of a lighting fixture showing our new design;
FIG. 2 is a rear elevation view thereof showing a support structure as environment only;
FIG. 3 is a right side elevation view thereof showing a support structure as environment only, the left side elevation view being a mirror image thereof;
FIG. 4 is a top plan view thereof showing a support structure as environment only, the bottom plan view being a mirror image thereof;
FIG. 5 is an enlarged cross-sectional view thereof taken along the line 5-5 in FIG. 1 showing a support structure as environment only;
FIG. 6 is an enlarged cross-sectional view thereof taken along the line 6-6 in FIG. 1;
FIG. 7 is another front elevation view thereof showing a name plate as environment only;
FIG. 8 is another front elevation view thereof showing a wall section and a name plate as environment only;
FIG. 9 is a fragmentary front perspective view thereof showing light rays as indicative of environmental operation that forms no part of the claimed design; and,
FIG. 10 is a fragmentary rear perspective view thereof showing light rays as indicative of environmental operation that forms no part of the claimed design.
The broken lines on the drawings represent environment only and form no part of the claimed design.