The ornamental design for a bonnet, as shown and described.
FIG. 1 is a left front perspective view of a bonnet showing my new design in use condition.
FIG. 2 is an enlarged left front perspective view thereof.
FIG. 3 is a front elevational view of thereof.
FIG. 4 is a right side elevational view thereof.
FIG. 5 is a rear prespective view thereof.
FIG. 6 is a left side elevational view thereof; and,
FIG. 7 is a top plan view thereof.
The rear and bottom form no part of my claimed design.
The broken line showing of the machine in FIG. 1, emblem throughout, and the inside portion of FIG. 5, is included for the purpose of illustrating environmental structure and forms no part of the claimed design.