Fix not-Flip-Mode flag turning off when returning from options menu

We need to check for graphics.setflipmode, not graphics.flipmode,
because graphics.flipmode only gets assigned at the end of the frame
(due to the deferred callback). Otherwise, returning from the options
menu would always turn flag 73 on, which would make you ineligible to
get the Flip Mode trophy, even if you're in Flip Mode.

Author: InfoTeddy

desktop_version/src/Game.cpp

@@ -6874,7 +6874,7 @@ void Game::returntoingame(void)
         gamestate = MAPMODE;
         DEFER_CALLBACK(setflipmode);
         DEFER_CALLBACK(setfademode);
-        if (!map.custommode && !graphics.flipmode)
+        if (!map.custommode && !graphics.setflipmode)
         {
             obj.flags[73] = true;
         }