The ornamental design for a handguard, as shown and described.
FIG. 1 is a perspective view of a hand guard showing my new design separately for clarity of illustration;
FIG. 2 is a top plan view thereof;
FIG. 3 is a front view thereof;
FIG. 4 is a top plan view thereof shown in an assembled condition with a second mirror image hand guard and a common handle used on a wheeled device such as a bicycle or tricycle, or motor wheeled device; and,