The ornamental design for a printer, as shown and described.
FIG. 1 is a front, top, and right side perspective view of a printer;
FIG. 2 is a front, top, and left side perspective view thereof;
FIG. 3 is a front elevational view thereof;
FIG. 4 is a rear elevational view thereof;
FIG. 5 is a left side elevational view thereof;
FIG. 6 is a right side elevational view thereof; and,
FIG. 7 is a top plan view thereof.
The broken lines immediately adjacent to the shaded areas, encompassing unshaded regions, represent the bounds of the claim, while all other broken lines are directed to environment and are for illustrative purposes only; the broken lines form no part of the claimed design.