Plumbing fixture

FIG. 1 is an isometric view of a front, top, and left side of an ornamental design for the plumbing fixture embodying our new design;

FIG. 2 is a front elevational view thereof;

FIG. 3 is a left side elevational view thereof, the right side elevational view thereof being a mirror image thereof;

FIG. 4 is a rear elevational view thereof;

FIG. 5 is a top plan view thereof; and,

FIG. 6 is a bottom plan view thereof.

The broken lines in the drawings depict environment subject matter only and form no part of the claimed design.