Fix error in cheb_grad(...)

- Vectors with overlapping memory are fixed.

include/cheb_utils.txx

@@ -1209,8 +1209,8 @@ void cheb_grad(const Vector<T>& A, int deg, Vector<T>& B, mem::MemoryManager* me
 
   // Create work buffers
   T* buff=mem::aligned_new<T>(2*n_coeff_*dof,mem_mgr);
-  Vector<T> A_(n_coeff_*dof,buff+n_coeff_*0,false); A_.SetZero();
-  Vector<T> B_(n_coeff_*dof,buff+n_coeff_*1,false); B_.SetZero();
+  Vector<T> A_(n_coeff_*dof,buff+n_coeff_*dof*0,false); A_.SetZero();
+  Vector<T> B_(n_coeff_*dof,buff+n_coeff_*dof*1,false); B_.SetZero();
 
   {// Rearrange data
     size_t indx=0;