Fix invocation summary log destination

Change-Id: I856b2123e49972b4cc0c6071f353e237c1403be6
diff --git a/korapxmltool.shebang b/korapxmltool.shebang
index 3633107..c31f187 100644
--- a/korapxmltool.shebang
+++ b/korapxmltool.shebang
@@ -197,7 +197,7 @@
       workload_type="default"
     fi
     
-    echo "Auto-detected: workload=$workload_type, input=${total_input_gb_precise}GB, memory=${xmx_mb}MB" >&2
+    export KORAPXMLTOOL_AUTO_DETECT_MSG="Auto-detected: workload=$workload_type, input=${total_input_gb_precise}GB, memory=${xmx_mb}MB"
   fi
   EXTRA_OPTS+=("-Xmx${xmx_mb}m")
 fi