The ornamental design for a tire tread, as shown and described.
FIG. 1 is a side perspective view of a tire tread showing our new design, it being understood that the tread pattern is repeated throughout the circumference of the tire tread;
FIG. 2 is a front view thereof, the opposite side being identical thereto;
FIG. 3 is a side view of the right side; and,
FIG. 4 is a side view of the left side.
The broken lines showing portions of the sidewall and inner bead depict portion of the tire that form no part of the claimed design.