The ornamental design for a walllamp, as shown and described.
FIG. 1 is a perspective view of a wall lamp showing my 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.
FIG. 7 is a bottom plan view thereof; and,
FIG. 8 is a locally enlarged view of FIG. 1.
The broken lines in the drawings depict portions of the wall lamp that form no part of the claimed design. The additional broken lines surrounding the detail views in FIGS. 1 and 8 are for annotative purposes only and form no part thereof.