The ornamental design for luggage, as shown and described.
FIG. 1 shows a front perspective view of luggage;
FIG. 2 shows a front elevation view of the luggage of FIG. 1;
FIG. 3 shows a rear elevation view of the luggage of FIG. 1;
FIG. 4 shows a right elevation view of the luggage of FIG. 1;
FIG. 5 shows a left elevation view of the luggage of FIG. 1;
FIG. 6 shows a top view of the luggage of FIG. 1; and,
FIG. 7 shows a bottom view of the luggage of FIG. 1.
In FIGS. 1-7, the broken lines and the unshaded areas within the broken lines illustrate portions of the luggage and form no part of the claimed invention.