The ornamental design for a walllamp, as shown and described.
FIG. 1 is a perspective view of my new wall lamp;
FIG. 2 is a front elevational view of my new wall lamp;
FIG. 3 is a rear elevational view of my new wall lamp, opposite that of FIG. 2;
FIG. 4 is a side elevational view of my new wall lamp;
FIG. 5 is another side elevational view of my new wall lamp from a side opposite that of FIG. 4;
FIG. 6 is a top view of my new wall lamp; and,
FIG. 7 is a bottom view of my new wall lamp.
The broken line showing of portions of the wall lamp in the figures is included for the purpose of illustrating environmental structure and forms no part of the claimed design.