python/retrace: Keep addresses as strings.

To simplify looking up these in the trace.

src/gallium/state_trackers/python/retrace/model.py

@@ -89,7 +89,7 @@ class Pointer(Node):
         visitor.visit_pointer(self)
         
     def __str__(self):
-        return hex(self.address)
+        return self.address
 
 
 class Call:

src/gallium/state_trackers/python/retrace/parser.py

@@ -316,8 +316,6 @@ class TraceParser(XmlParser):
         address = self.character_data()
         self.element_end('ptr')
 
-        address = int(address, 16)
-        
         return Pointer(address)