Fix the mistakes in manual and minor errors.

1. Fix the mistakes in manual.
2. Fix the minor errors in Stack and LogSoftmax functions.

source/tensor/core/shape/Stack.h

@@ -31,7 +31,7 @@ namespace nts { // namespace nts(NiuTrans.Tensor)
 void _Stack(const TensorList * smalls, XTensor * t, int dim);
 
 /* stack small tensors into a big tensor along with a dimension (return an XTensor structure) */
-XTensor Stack(const TensorList &list, int dim);
+XTensor Stack(const TensorList &smalls, int dim);
 
 /* stack small tensors into a big tensor along with a dimension */
 void Stack(const TensorList &smalls, XTensor &t, int dim);

source/tensor/function/LogSoftmax.h

@@ -36,9 +36,6 @@ XTensor LogSoftmax(const XTensor &x, int leadDim);
 /* log scale softmax y = log(e^x / \sum_{i} e^{x_i}) (with both argument of x and y) */
 void LogSoftmax(const XTensor &x, XTensor &y, int leadDim);
 
-/* log scale softmax y = log(e^x / \sum_{i} e^{x_i}) (with both argument of x and y) */
-void LogSoftmax(const XTensor &x, XTensor &y, int leadDim);
-
 /* de/dx */
 void _LogSoftmaxBackward(XTensor * gold, XTensor * y, XTensor * x, 
                          XTensor * dedy, XTensor * dedx,