Fix windows build
Fix windows build

Summary: Closes https://github.com/caffe2/caffe2/pull/214

Differential Revision: D4755224

Pulled By: asaadaldien

fbshipit-source-id: 8a3c6d13319aecc0bf700bad2b3e9ed2a53571e9

pietern/caffe2,xzturn/caffe2,bwasti/caffe2,sf-wind/caffe2,bwasti/caffe2,bwasti/caffe2,pietern/caffe2,sf-wind/caffe2,pietern/caffe2,Yangqing/caffe2,davinwang/caffe2,davinwang/caffe2,pietern/caffe2,Yangqing/caffe2,pietern/caffe2,caffe2/caffe2,xzturn/caffe2,xzturn/caffe2,xzturn/caffe2,davinwang/caffe2,sf-wind/caffe2,Yangqing/caffe2,bwasti/caffe2,Yangqing/caffe2,sf-wind/caffe2,xzturn/caffe2,bwasti/caffe2,davinwang/caffe2,sf-wind/caffe2,Yangqing/caffe2,davinwang/caffe2