Update mxnet third_party folder

tools/mxnet-update

@@ -6,8 +6,8 @@ tools=$(dirname ${0})
 src=${tools}/../src
 third_party=${tools}/../third_party
 
-identifier=incubator-mxnet
-repository=https://github.com/apache/incubator-mxnet.git
+identifier=mxnet
+repository=https://github.com/apache/incubator-${identifier}.git
 
 mkdir -p ${third_party}
 
@@ -16,7 +16,7 @@ if [ -d "${third_party}/${identifier}" ]; then
     git -C "${third_party}/${identifier}" reset --hard origin/master
 else
     echo "Clone ${repository}..."
-    git -C "${third_party}" clone --recursive ${repository}
+    git -C "${third_party}" clone --recursive ${repository} ${identifier}
 fi
 
 # echo "Update '../src/mxnet-metadata.json'"