Fix CMakelists.txt for caffe2/contrib
Fix CMakelists.txt for caffe2/contrib

Differential Revision: D5460222

fbshipit-source-id: 765c94e48f9831b176244060c3e126097f5bb924

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