(OSX) Don't leak memory for NSScreen objects

apple/common/RAGameView.m

@@ -223,6 +223,8 @@ static RAScreen* get_chosen_screen()
 {
    unsigned monitor = g_settings.video.monitor_index;
 
+   @autoreleasepool
+   {
       if (monitor >= RAScreen.screens.count)
       {
          RARCH_WARN("video_monitor_index is greater than the number of connected monitors; using main screen instead.\n");
@@ -231,6 +233,7 @@ static RAScreen* get_chosen_screen()
 
       return RAScreen.screens[monitor];
    }
+}
 
 bool apple_gfx_ctx_init()
 {