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

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

Change-Id: Ibd914508a7ffdde5e66aaed07f873a1e6d98db8e
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>