The ornamental design for a usbsocket, as shown and described.
FIG. 1 is a perspective view of a USB socket 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 side elevational view thereof;
FIG. 5 is a right side elevational view thereof;
FIG. 6 is a top plan view thereof; and,
FIG. 7 is a bottom plan view thereof.
The broken line depicts internal elements of the USB socket shown in FIGS. 1, 2, 3, 6 and 7 is unclaimed subject matter and forms no part of the claimed design.