update C++ example so it is easier to run (#12397)
update C++ example so it is easier to run (#12397)

* update example so it is easier to run

* updated per feedback; removed CPP prerequisite

mbaijal/incubator-mxnet,leezu/mxnet,mbaijal/incubator-mxnet,dmlc/mxnet,tlby/mxnet,ForkedReposBak/mxnet,sxjscience/mxnet,eric-haibin-lin/mxnet,larroy/mxnet,ptrendx/mxnet,ptrendx/mxnet,sxjscience/mxnet,larroy/mxnet,larroy/mxnet,apache/incubator-mxnet,mbaijal/incubator-mxnet,apache/incubator-mxnet,zhreshold/mxnet,zhreshold/mxnet,DickJC123/mxnet,ptrendx/mxnet,sxjscience/mxnet,leezu/mxnet,dmlc/mxnet,ForkedReposBak/mxnet,dmlc/mxnet,tlby/mxnet,tlby/mxnet,szha/mxnet,larroy/mxnet,leezu/mxnet,apache/incubator-mxnet,sxjscience/mxnet,larroy/mxnet,yajiedesign/mxnet,mbaijal/incubator-mxnet,reminisce/mxnet,eric-haibin-lin/mxnet,ForkedReposBak/mxnet,mbaijal/incubator-mxnet,eric-haibin-lin/mxnet,dmlc/mxnet,zhreshold/mxnet,mbaijal/incubator-mxnet,mbaijal/incubator-mxnet,reminisce/mxnet,eric-haibin-lin/mxnet,zhreshold/mxnet,reminisce/mxnet,ForkedReposBak/mxnet,reminisce/mxnet,leezu/mxnet,sxjscience/mxnet,dmlc/mxnet,ForkedReposBak/mxnet,ForkedReposBak/mxnet,reminisce/mxnet,szha/mxnet,dmlc/mxnet,sxjscience/mxnet,ptrendx/mxnet,ptrendx/mxnet,yajiedesign/mxnet,dmlc/mxnet,yajiedesign/mxnet,ForkedReposBak/mxnet,yajiedesign/mxnet,mbaijal/incubator-mxnet,eric-haibin-lin/mxnet,ForkedReposBak/mxnet,yajiedesign/mxnet,sxjscience/mxnet,szha/mxnet,tlby/mxnet,ptrendx/mxnet,ptrendx/mxnet,larroy/mxnet,tlby/mxnet,leezu/mxnet,tlby/mxnet,reminisce/mxnet,tlby/mxnet,sxjscience/mxnet,szha/mxnet,leezu/mxnet,leezu/mxnet,yajiedesign/mxnet,yajiedesign/mxnet,dmlc/mxnet,ptrendx/mxnet,reminisce/mxnet,yajiedesign/mxnet,mbaijal/incubator-mxnet,eric-haibin-lin/mxnet,zhreshold/mxnet,sxjscience/mxnet,ptrendx/mxnet,reminisce/mxnet,zhreshold/mxnet,szha/mxnet,zhreshold/mxnet,zhreshold/mxnet,szha/mxnet,zhreshold/mxnet,DickJC123/mxnet,leezu/mxnet,dmlc/mxnet,DickJC123/mxnet,eric-haibin-lin/mxnet,eric-haibin-lin/mxnet,szha/mxnet,DickJC123/mxnet,larroy/mxnet,ptrendx/mxnet,larroy/mxnet,reminisce/mxnet,larroy/mxnet,leezu/mxnet,ForkedReposBak/mxnet,tlby/mxnet,tlby/mxnet,szha/mxnet,szha/mxnet,tlby/mxnet,apache/incubator-mxnet,yajiedesign/mxnet,eric-haibin-lin/mxnet,reminisce/mxnet