The ornamental design for a screwdriver, as shown and described.
FIG. 1 is a perspective view of a screwdriver showing my new design;
FIG. 2 is a left-side elevation view thereof;
FIG. 3 is a right-side elevation view thereof;
FIG. 4 is a top plan view thereof;
FIG. 5 is a bottom plan view thereof;
FIG. 6 is an enlarged front elevation view thereof;
FIG. 7 is an enlarged rear elevation view thereof; and,
FIG. 8 is an enlarged perspective view of a front portion thereof.
The portions shown in broken lines form no part of the claimed design.
The screwdriver is shown with a symbolic break in its length. The appearance of any portion of the article between the break lines forms no part of the claimed design.