We claim the ornamental design for a motorcycle saddlebag, as shown and described.
FIG. 1 is a side view of the motorcycle saddlebag
FIG. 2 is a rear view of the design shown in FIG. 1; and,
FIG. 3 is a top view of the design shown in FIG. 1.
The broken line showing of the environment is for illustrative purposes only and forms no part of the claimed design. The broken lines which define the boundaries of the claimed design form no part thereof.