[CMake] fix PACKAGE_EXTRA_MACROS use

CMakeLists.txt

@@ -13,7 +13,6 @@ OPTION(SUFFIX_SO_VERSION "Suffix library name with its version" ON)
 SET(PROJECT_USE_CMAKE_EXPORT TRUE)
 SET(CXX_DISABLE_WERROR TRUE)
 SET(CMAKE_CXX_STANDARD 11)
-SET(PACKAGE_EXTRA_MACROS "set(TALOS_DATA_PREFIX ${CMAKE_INSTALL_PREFIX})")
 
 # JRL-cmakemodule setup
 INCLUDE(cmake/base.cmake)
@@ -51,3 +50,4 @@ FOREACH(dir config gazebo meshes robots urdf srdf launch)
 ENDFOREACH(dir)
 
 INSTALL(FILES package.xml DESTINATION share/${PROJECT_NAME})
+SET(PACKAGE_EXTRA_MACROS "set(TALOS_DATA_PREFIX ${CMAKE_INSTALL_PREFIX})")