Fix typos KeyDown => KeysDown

examples/directx9_example/imgui_impl_dx9.cpp

@@ -309,7 +309,7 @@ bool    ImGui_ImplDX9_Init(void* hwnd, IDirect3DDevice9* device)
     io.BackendFlags |= ImGuiBackendFlags_HasMouseCursors;   // We can honor GetMouseCursor() values (optional)
     io.BackendFlags |= ImGuiBackendFlags_HasSetMousePos;    // We can honor io.WantSetMousePos requests (optional, rarely used)
 
-    // Keyboard mapping. ImGui will use those indices to peek into the io.KeyDown[] array that we will update during the application lifetime.
+    // Keyboard mapping. ImGui will use those indices to peek into the io.KeysDown[] array that we will update during the application lifetime.
     io.KeyMap[ImGuiKey_Tab] = VK_TAB;
     io.KeyMap[ImGuiKey_LeftArrow] = VK_LEFT;
     io.KeyMap[ImGuiKey_RightArrow] = VK_RIGHT;