The ornamental design for a faucet, as shown and described.
FIG. 1 is a perspective view of a faucet showing my new design;
FIG. 2 is a front elevational view thereof;
FIG. 3 is a right side view thereof, the opposite side being a mirror image of the side shown;
FIG. 4 is a rear view thereof;
FIG. 5 is a top plan view thereof; and,
FIG. 6 is a bottom view thereof.
The broken lines shown in the drawing views are included for the purpose of illustrating a portion of the faucet that form no part of the claimed design.