Fixed onnx test failures when run on a cpu backend (#3764)
Fixed onnx test failures when run on a cpu backend (#3764)

* Fixed onnx test failures when run on a cpu backend

* Updated check_torch_conversion function to include output comparison

sxjscience/tvm,Laurawly/tvm-1,dmlc/tvm,Huyuwei/tvm,dmlc/tvm,Huyuwei/tvm,sxjscience/tvm,dmlc/tvm,sxjscience/tvm,Laurawly/tvm-1,tqchen/tvm,sxjscience/tvm,sxjscience/tvm,tqchen/tvm,sxjscience/tvm,Laurawly/tvm-1,tqchen/tvm,dmlc/tvm,dmlc/tvm,tqchen/tvm,Laurawly/tvm-1,dmlc/tvm,Laurawly/tvm-1,dmlc/tvm,sxjscience/tvm,Huyuwei/tvm,Huyuwei/tvm,tqchen/tvm,Laurawly/tvm-1,Huyuwei/tvm,tqchen/tvm,sxjscience/tvm,Huyuwei/tvm,Huyuwei/tvm,tqchen/tvm,Huyuwei/tvm,dmlc/tvm,tqchen/tvm,Laurawly/tvm-1,dmlc/tvm,Laurawly/tvm-1,tqchen/tvm,Laurawly/tvm-1,tqchen/tvm,sxjscience/tvm,Laurawly/tvm-1,Huyuwei/tvm