Fix a test to check duplicated phandles am: 718007765a

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

Change-Id: I909be551c58c7891716a4f53fcb8c2eceef6fd52
Signed-off-by: Automerger Merge Worker <[email protected]>