Revert "CMake version.cpp: switch back to add_custom_target"

Author: peterschrammel

src/util/CMakeLists.txt

@@ -30,20 +30,18 @@ endif()
 
 file(WRITE ${CMAKE_CURRENT_BINARY_DIR}/version.cpp.in
   "const char *CBMC_VERSION=\"@CBMC_RELEASE@ (@GIT_INFO@)\";\n")
-add_custom_target(
-  generate_version_cpp
+add_custom_command(
+  OUTPUT version.cpp
   COMMAND ${CMAKE_COMMAND}
     -D CBMC_SOURCE_DIR=${CBMC_SOURCE_DIR}
     -D CUR=${CMAKE_CURRENT_BINARY_DIR}
     -P ${CMAKE_BINARY_DIR}/version.cmake
-    )
+)
 
 add_library(util
   ${sources}
   version.cpp)
 
-add_dependencies(util generate_version_cpp)
-
 generic_includes(util)
 
 target_link_libraries(util big-int langapi)