I claim the ornamental design for a computing device, as shown and described.
FIG. 1 is a front perspective view of a computing device in an open state;
FIG. 2 is a front view thereof;
FIG. 3 is a rear view thereof;
FIG. 4 is a right side view thereof;
FIG. 5 is a left side view thereof;
FIG. 6 is a top view thereof;
FIG. 7 is a bottom view thereof; and,
FIG. 8 is a rear perspective view thereof with the computing device in a closed state.
Broken lines shown in the drawings illustrate portions of the keyboard and form no part of the claimed design. The short-dash long-dash broken lines are boundary lines and form no part of the claimed design.