Fix StackOverflow on ToString method am: 89ff8c6fbe am: 0264bfe2ce am: 15c35de51e

Original change: https://android-review.googlesource.com/c/platform/external/obex/+/2269058

Change-Id: Iaf541ac2ac61581160269d435b0b299bccee4f8a
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>
diff --git a/src/com/android/obex/HeaderSet.java b/src/com/android/obex/HeaderSet.java
index 15c128d..d1afe4f 100644
--- a/src/com/android/obex/HeaderSet.java
+++ b/src/com/android/obex/HeaderSet.java
@@ -729,7 +729,7 @@
 
     @Override
     public String toString() {
-        return "HeaderSet " + this + ": NAME=" + mName;
+        return "HeaderSet " + System.identityHashCode(this) + ": NAME=" + mName;
     }
 
     public String dump() {