Created by: wangkuiyi

For the purpose of this change, please refer to https://github.com/PaddlePaddle/Paddle/pull/11550/files#diff-e8a3b4cd5fff7d282b01918ab749d61aR16

The CMakeLists.txt file for C-API includes a call to CMake function SWIG_ADD_MODULE, which is deprecated and would cause CMake warnings like:

CMake Deprecation Warning at /usr/local/Cellar/cmake/3.10.0/share/cmake/Modules/UseSWIG.cmake:231 (message):
  SWIG_ADD_MODULE is deprecated.  Use SWIG_ADD_LIBRARY instead.