The ornamental design for a bassinet, as shown and described.
FIG. 1 is a perspective view of the bassinet in accordance with a first form of the present invention;
FIG. 2 is a front view thereof;
FIG. 3 is a top view thereof;
FIG. 4 is a right side view thereof;
FIG. 5 is a left side view thereof;
FIG. 6 is a rear view thereof; and,
FIG. 7 is a bottom view thereof.
The portions of FIGS. 1-7 that are shown in non-shading broken lines are unclaimed environmental subject matter only and form no part of the claimed design.