Merge pull request cocos2d#9568 from vovkasm/pull/fix-cmake-link

cmake: fix tests linking

CMakeLists.txt

@@ -256,21 +256,8 @@ cocos_find_package(TIFF TIFF REQUIRED)
 cocos_find_package(WEBSOCKETS WEBSOCKETS REQUIRED)
 cocos_find_package(CURL CURL REQUIRED)
 
-# flatbuffers (not prebuilded, exists as source)
-# TODO: for now we can't use upstream flatbuffers because these files:
-#  cocos/editor-support/cocostudio/CSParseBinary_generated.h
-# was generated by concrete version of flatbuffers compiler
-# and source file not provided. So these files can be
-# compiled only with our in-source version of flatbuffers
-## if(USE_PREBUILT_LIBS)
-  add_subdirectory(external/flatbuffers)
-  set(FLATBUFFERS_INCLUDE_DIRS ${CMAKE_CURRENT_SOURCE_DIR}/external)
-  set(FLATBUFFERS_LIBRARIES flatbuffers)
-## else()
-##  cocos_find_package(Flatbuffers REQUIRED FLATBUFFERS_LIBRARIES)
-##  set(FLATBUFFERS_INCLUDE_DIRS ${FLATBUFFERS_INCLUDE_DIRS})
-## endif()
-message(STATUS "Flatbuffers libs: ${FLATBUFFERS_LIBRARIES}")
+add_subdirectory(external/flatbuffers)
+set(FLATBUFFERS_INCLUDE_DIRS ${CMAKE_CURRENT_SOURCE_DIR}/external)
 message(STATUS "Flatbuffers include dirs: ${FLATBUFFERS_INCLUDE_DIRS}")