More file selector fixes

Fix a freeze that occurs when you move or delete a file in the
file manager
Make file sort buttons work again

Change-Id: Ifcb68edf3c29c475946d538748729485d0840842
diff --git a/gui/objects.hpp b/gui/objects.hpp
index 3a39fe5..047b66b 100644
--- a/gui/objects.hpp
+++ b/gui/objects.hpp
@@ -496,6 +496,7 @@
 	COLOR mFontHighlightColor;
 	int startSelection;
 	bool updateFileList;
+	pthread_mutex_t updateFileListmutex;
 };
 
 class GUIListBox : public RenderObject, public ActionObject