C++: Address review comments.

cpp/ql/src/semmle/code/cpp/models/implementations/Strset.qll

@@ -40,9 +40,6 @@ private class StrsetFunction extends ArrayFunction, DataFlowFunction, AliasFunct
     // flow from the input string to the output string
     input.isParameter(0) and
     output.isReturnValue()
-    or
-    input.isParameterDeref(0) and
-    output.isReturnValueDeref()
   }
 
   override predicate parameterNeverEscapes(int index) { none() }