Fix typo (#2595)

thanks @icemelon9, this is merged

topi/include/topi/detail/ravel_unravel.h

@@ -44,7 +44,7 @@ inline Expr RavelIndex(Array<Var> indices, Array<Expr> shape) {
 *
 * \return The coordinate corresponding to the 1D index
 */
-inline Array<Expr> UnavelIndex(Expr idx, Array<Expr> shape) {
+inline Array<Expr> UnravelIndex(Expr idx, Array<Expr> shape) {
   std::vector<Expr> indices;
 
   for (int i = static_cast<int>(shape.size()) - 1; i >= 0; --i) {

topi/include/topi/transform.h

@@ -188,7 +188,7 @@ inline Tensor reshape(const Tensor& x,
   auto x_shape = x->shape;
   return compute(
     newshape, [&](const Array<Var>& indices) {
-      return x(UnavelIndex(RavelIndex(indices, newshape), x_shape));
+      return x(UnravelIndex(RavelIndex(indices, newshape), x_shape));
     }, name, tag);
 }
 
@@ -566,7 +566,7 @@ inline Tensor take(const Tensor& a,
           for (size_t j = 0; j < indices->shape.size(); ++j) {
             indices_position.push_back(out_index[j]);
           }
-          return a(UnavelIndex(indices(indices_position), a_shape));
+          return a(UnravelIndex(indices(indices_position), a_shape));
         }, name, tag);
 }