Fix a bug when dumping locks from signal catcher am: 0cc7f6bcce am: bfcb8faa34

Original change: https://android-review.googlesource.com/c/platform/art/+/2241205

Change-Id: Ia29bc585c7368834a6432c3371b38a8037c4f0f4
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>