Merge pull request #532 from Nizernizer/fix/string-hash-enhance

fix: range hash.

Author: lostsnow

dongtai-core/src/main/java/io/dongtai/iast/core/handler/hookpoint/controller/impl/PropagatorImpl.java

@@ -221,6 +221,7 @@ private static void trackTaintRange(PropagatorNode propagatorNode, MethodEvent e
             tgtHash = TaintPoolUtils.getStringHash(tgt);
             oldTaintRanges = getTaintRanges(tgt);
         } else if (TaintPosition.hasReturn(targetLocs)) {
+            tgt = event.returnInstance;
             tgtHash = TaintPoolUtils.getStringHash(tgt);
         } else if (TaintPosition.hasParameter(targetLocs)) {
             for (TaintPosition targetLoc : targetLocs) {