The ornamental design for an inflatablelegrest, as shown and described.
FIG. 1 is a front perspective view of an inflatable leg rest, showing our new design;
FIG. 2 is a front view thereof;
FIG. 3 is a rear view thereof;
FIG. 4 is a side view thereof;
FIG. 5 is an opposing side view thereof;
FIG. 6 is a top view thereof; and,
FIG. 7 is a bottom view thereof.
The broken lines are included for the purpose of illustrating environmental portions of the inflatable leg rest that form no part of the claimed design.