Created by: guoshengCS

Warning in roi_pool_op when compiling. As following:

In file included from /Users/baidu/Documents/codeRep/paddle-master/Paddle/paddle/operators/roi_pool_op.cc:15:
/Users/baidu/Documents/codeRep/paddle-master/Paddle/paddle/operators/roi_pool_op.h:165:28: warning: comparison of integers of different signs: 'size_t' (aka 'unsigned long') and 'int' [-Wsign-compare]
      for (size_t n = 0; n < rois_num; ++n) {
                         ~ ^ ~~~~~~~~