[clang] Use PRIVATE in target_link_libraries

I'd missed this one in r319840 because I hadn't been configuring with an
order file before.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@319950 91177308-0d34-0410-b5e6-96231b3b80d8

tools/driver/CMakeLists.txt

@@ -123,7 +123,7 @@ if(CLANG_ORDER_FILE AND (LD64_EXECUTABLE OR GOLD_EXECUTABLE))
   if("${ORDER_FILE}" STREQUAL "\n")
     set_property(DIRECTORY APPEND PROPERTY CMAKE_CONFIGURE_DEPENDS ${CLANG_ORDER_FILE})
   elseif(LINKER_ORDER_FILE_WORKS)
-    target_link_libraries(clang ${LINKER_ORDER_FILE_OPTION})
+    target_link_libraries(clang PRIVATE ${LINKER_ORDER_FILE_OPTION})
     set_target_properties(clang PROPERTIES LINK_DEPENDS ${CLANG_ORDER_FILE})
   endif()
 endif()