The ornamental design for a ceilingpanel, as shown and described.
FIG. 1 is a top plan view of a ceiling panel showing our new design;
FIG. 2 is a perspective view thereof;
FIG. 3 is side elevation view thereof;
FIG. 4 is a perspective view of the ceiling panel shown in FIGS. 1-3. The broken lines showing suspension hardware and like ceiling panels for the purpose of illustrating the environment and such broken lines form no part of the claimed design; and,
FIG. 5 is a top plan view of FIG. 4. The broken lines showing suspension hardware and like ceiling panels for the purpose of illustrating the environment and such broken lines form no part of the claimed design.