The ornamental design for fluted deck, as shown and described.
FIG. 1 is a rear view of a fluted deck;
FIG. 2 is a partial, sectional view of the bottom of the fluted deck showing internal features, taken from the line 2-2 in FIGS. 1 and 6;
FIG. 3 is a partial, sectional view of the top of the fluted deck showing internal features taken from the line 3-3 in FIGS. 1 and 6;
FIG. 4 is a side view of the fluted deck;
FIG. 5 is a partial top, detail view of the fluted deck shown in FIG. 3;
FIG. 6 is a right, rear perspective view of the fluted deck; and,
FIG. 7 is front view of the fluted deck.
The broken, dashed lines shown in the various figures are included for the purpose of illustrating environment and do not form any part of the claimed design.