ControlTest: Fix cppcheck false positives.

Suppress a couple cppcheck memleak false positives.

AtlasTest/ControlTest/test/SGDataLink_test.cxx

 /*
-  Copyright (C) 2002-2023 CERN for the benefit of the ATLAS collaboration
+  Copyright (C) 2002-2024 CERN for the benefit of the ATLAS collaboration
 */
 
 #undef NDEBUG
@@ -230,6 +230,7 @@ namespace Athena_test
     assert(liint.index() == 1);
     assert(liint.dataID() == "a vector");
     cout << "*** DataLink_test StoreGate OK ***\n\n" <<endl;
+    // cppcheck-suppress memleak; false positive
   }
 
   void dummyToRemoveWarning(const Foo&) 
@@ -333,6 +334,7 @@ namespace Athena_test
     std::cout << "xxx " << der << " " << link.cptr() << "\n";
     //assert (link.cptr() == der);
     cout << "*** DataLink_test FwdBase OK ***\n\n" <<endl;
+    // cppcheck-suppress memleak; false positive
   }
 } //end namespace