git: openjdk/jdk-sandbox: json: More logic refinement for path error msg

[duke]

Changeset: f3860565
Branch: json
Author:    Justin Lu <justin.lu at oracle.com>
Date:      2025-08-13 13:40:53 +0000
URL:       https://git.openjdk.org/jdk-sandbox/commit/f3860565a5b0233be71863bfe42a169af413fbd7

More logic refinement for path error msg

! src/java.base/share/classes/jdk/internal/util/json/Utils.java
! test/jdk/java/util/json/TestAssertion.java