Change to unsigned int

tsk/pool/tsk_pool.hpp

@@ -47,7 +47,7 @@ class TSKPool {
 
   virtual const std::vector<range> unallocated_ranges() const { return {}; };
 
-  TSK_IMG_INFO *getTSKImgInfo(int index) const { 
+  TSK_IMG_INFO *getTSKImgInfo(unsigned int index) const { 
       if (index < _members.size()) {
           return _members[index].first;
       }