Fix building background_task example plugin on headless

examples/background_task/CMakeLists.txt

@@ -2,11 +2,8 @@ cmake_minimum_required(VERSION 3.13 FATAL_ERROR)
 
 project(background_task CXX C)
 
-file(GLOB SOURCES
-	src/*.cpp
-	src/*.h)
-
-add_library(background_task SHARED ${SOURCES})
+add_library(background_task SHARED
+        src/backgroundtask.cpp)
 
 if(NOT BN_API_BUILD_EXAMPLES AND NOT BN_INTERNAL_BUILD)
     # Out-of-tree build
@@ -19,7 +16,8 @@ if(NOT BN_API_BUILD_EXAMPLES AND NOT BN_INTERNAL_BUILD)
     add_subdirectory(${BN_API_PATH} api)
 endif()
 
-target_link_libraries(background_task binaryninjaui)
+target_link_libraries(${PROJECT_NAME}
+        binaryninjaapi)
 
 set_target_properties(background_task PROPERTIES
     CXX_STANDARD 17
@@ -29,8 +27,4 @@ set_target_properties(background_task PROPERTIES
 	POSITION_INDEPENDENT_CODE ON
 	LIBRARY_OUTPUT_DIRECTORY ${CMAKE_BINARY_DIR}/out/bin)
 
-if(BN_INTERNAL_BUILD)
-	ui_plugin_rpath(background_task)
-endif()
-
 bn_install_plugin(${PROJECT_NAME})