Fix a test to check duplicated phandles am: 718007765a am: bc2c5f2384 am: cee5ba9a09

Original change: https://android-review.googlesource.com/c/platform/system/libufdt/+/2385752

Change-Id: I46634a9110876b62698a121c2f0da60d32db593e
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>