We claim the ornamental design for a retail display fixture, as shown and described.
FIG. 1 is a front perspective view of a retail display fixture;
FIG. 2 is a back perspective view of the retail display fixture;
FIG. 3 is a front elevational view thereof;
FIG. 4 is a back elevational view thereof;
FIG. 5 is a right elevational view thereof;
FIG. 6 is a left elevational view thereof;
FIG. 7 is a top plan view thereof; and,
FIG. 8 is a bottom plan view thereof.
The broken lines shown in the drawings of the retail display fixture are for the purpose of illustrating portions of the article and form no part of the claimed design.