xfixes: calloc, not malloc the cursorScreenRec

Debugging NULL pointers is significantly easier than random memory.
Plus, if new fields (such as pointer barriers) are added they may just be
properly initialised.

Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>
Reviewed-by: Keith Packard <keithp@keithp.com>

xfixes/cursor.c

@@ -1045,7 +1045,7 @@ XFixesCursorInit (void)
 	ScreenPtr	pScreen = screenInfo.screens[i];
 	CursorScreenPtr	cs;
 
-	cs = (CursorScreenPtr) malloc(sizeof (CursorScreenRec));
+	cs = (CursorScreenPtr) calloc(1, sizeof (CursorScreenRec));
 	if (!cs)
 	    return FALSE;
 	Wrap (cs, pScreen, CloseScreen, CursorCloseScreen);