riched20: Handle WM_DESTROY in the host.

dlls/riched20/editor.c

@@ -4277,9 +4277,6 @@ LRESULT ME_HandleMessage(ME_TextEditor *editor, UINT msg, WPARAM wParam,
   }
   case WM_CREATE:
     return ME_WmCreate(editor, lParam, unicode);
-  case WM_DESTROY:
-    ME_DestroyEditor(editor);
-    return 0;
   case WM_SETCURSOR:
   {
     POINT cursor_pos;

dlls/riched20/txthost.c

@@ -780,6 +780,10 @@ static LRESULT RichEditWndProc_common( HWND hwnd, UINT msg, WPARAM wparam,
     editor = host->editor;
     switch (msg)
     {
+    case WM_DESTROY:
+        ITextHost_Release( &host->ITextHost_iface );
+        return 0;
+
     case WM_ERASEBKGND:
     {
         HDC hdc = (HDC)wparam;