The ornamental design for a “lamp cup,” as shown and described.
FIG. 1 is a front perspective view of a lamp cup 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 showing of inner surfaces of FIG. 6 is for the purpose of illustrating portions of the article and forms no part of the claimed design. The broken lines showing bottom features of FIG. 7 are for the purpose of illustrating portions of the article and form no part of the claimed design.