The ornamental design for printer, as shown and described.
FIG. 1 is a perspective view of a printer showing my new design;
FIG. 2 is a front view of the printer;
FIG. 3 is a rear view of the printer;
FIG. 4 is a right view of the printer;
FIG. 5 is a left view of the printer;
FIG. 6 is a plan view of the printer;
FIG. 7 is a bottom view of the printer;
FIG. 8 is a cross-sectional view of the printer along lines 8-8 shown in FIG. 2; and,
FIG. 9 is an enlarged view of the printer.
The broken lines show portions of the design that form no part of the claim. The long dash-dot broken lines show the boundaries of the claim and form no part of the claimed design.