Fix the path to zlib.map in CMakeLists.txt.

CMakeLists.txt

@@ -166,7 +166,7 @@ endif()
 if(UNIX)
     # On unix-like platforms the library is almost always called libz
    set_target_properties(zlib zlibstatic PROPERTIES OUTPUT_NAME z)
-   set_target_properties(zlib PROPERTIES LINK_FLAGS "-Wl,--version-script,zlib.map")
+   set_target_properties(zlib PROPERTIES LINK_FLAGS "-Wl,--version-script,${CMAKE_CURRENT_SOURCE_DIR}/zlib.map")
 elseif(BUILD_SHARED_LIBS AND WIN32)
     # Creates zlib1.dll when building shared library version
     set_target_properties(zlib PROPERTIES SUFFIX "1.dll")