Put in safeguard against TypeError where cook is None

Author: Oliver Old

volatility/plugins/overlays/windows/win10.py

@@ -360,6 +360,9 @@ def TypeIndex(self):
         addr = self.obj_offset 
         indx = int(self.m("TypeIndex"))
 
+        if cook is None:
+            debug.error("Cannot obtain nt!ObHeaderCookie value")
+
         return ((addr >> 8) ^ cook ^ indx) & 0xFF
 
     def is_valid(self):