The ornamental design for a headlight for a motorcycle, as shown and described.
FIG. 1 is a perspective view from the front side of a headlight for a motorcycle.
FIG. 2 is a perspective view from the front side thereof.
FIG. 3 is a perspective view from the rear side thereof.
FIG. 4 is a perspective view from the rear side thereof.
FIG. 5 is a front elevation view thereof.
FIG. 6 is a rear elevation view thereof.
FIG. 7 is a left side elevation view thereof.
FIG. 8 is a right side elevation view thereof.
FIG. 9 is a top plan view thereof.
FIG. 10 is a bottom plan view thereof; and,
FIG. 11 is a referential view showing use thereof.
The portions of the headlight shown in broken lines are for the purpose of showing environmental structure only and form no part of the claimed design.