use CUDA version of AccuracyOp with top_k=1
use CUDA version of AccuracyOp with top_k=1

Summary: D4348953 added support for accuracy for top_k>1, which is only supported on CPU, requiring data to be copied to CUDA. But that diff did not take into account that we have top_k=1 version of AccuracyOp for CUDA. This diff ensures we use the CUDA version for top_k=1.

Differential Revision: D4607767

fbshipit-source-id: 8becda23890343043eb79ad04e4c6196e9010f0c

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