found by cppcheck
[client/Wayland/wlf_cliprdr.c:143] -> [client/Wayland/wlf_cliprdr.c:158]: (warning) Either the condition 'clipboard' is redundant or there is possible null pointer dereference: clipboard.
[client/Wayland/wlf_cliprdr.c:163] -> [client/Wayland/wlf_cliprdr.c:178]: (warning) Either the condition 'clipboard' is redundant or there is possible null pointer dereference: clipboard.