We claim the ornamental design for a printer, as shown and described.
FIG. 1 is a top perspective view of a printer showing our new design;
FIG. 2 is a front elevational view thereof;
FIG. 3 is a rear elevational view thereof;
FIG. 4 is a left end elevational view thereof; and,
FIG. 5 is a right end elevational view thereof.
The contour broken lines are shown in dash dash format, are for illustrative purposes only and form no part of the claimed design. The broken lines which define the bounds of the claimed design are illustrated in long dash short dash format and form no part thereof.