Update some incorrect comments in Dot::generate_adjoints (#2045)

src/ngraph/op/dot.cpp

@@ -173,11 +173,11 @@ void op::Dot::generate_adjoints(autodiff::Adjoints& adjoints, const NodeVector&
     J_shape.insert(J_shape.begin(), y_shape.begin(), y_shape.begin() + m_reduction_axes_count);
     K_shape.insert(K_shape.begin(), y_shape.begin() + J_shape.size(), y_shape.end());
 
-    auto y_reshaped = make_reshape_axes_to_front(y, J_shape, K_shape);               // KI
-    auto delta_dot_y_reshaped = make_shared<Dot>(delta, y_reshaped, K_shape.size()); // JI
+    auto y_reshaped = make_reshape_axes_to_front(y, J_shape, K_shape);               // KJ
+    auto delta_dot_y_reshaped = make_shared<Dot>(delta, y_reshaped, K_shape.size()); // IK.KJ->IJ
     adjoints.add_delta(x, delta_dot_y_reshaped);
 
     auto x_reshaped = make_reshape_axes_to_front(x, I_shape, J_shape);               // JI
-    auto x_reshaped_dot_delta = make_shared<Dot>(x_reshaped, delta, I_shape.size()); // JK
+    auto x_reshaped_dot_delta = make_shared<Dot>(x_reshaped, delta, I_shape.size()); // JI.IK->JK
     adjoints.add_delta(y, x_reshaped_dot_delta);
 }