Avoid duplicating return value computation.

git-svn-id: https://svn.erp5.org/repos/neo/trunk@2464 71dcc9de-d417-0410-9af5-da40c76e7ee4

neo/storage/database/btree.py

@@ -638,7 +638,8 @@ class BTreeDatabaseManager(DatabaseManager):
                 max_serial = tserial.maxKey(tid)
             except ValueError:
                 # No entry before pack TID, nothing to pack on this object.
-                return False
+                pass
+            else:
                 if tserial[max_serial][2] == '':
                     # Last version before/at pack TID is a creation undo, drop
                     # it too.