Fix a bug when dumping locks from signal catcher am: 0cc7f6bcce am: bfcb8faa34 am: dbb25b43c1

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

Change-Id: I506415d62d296e3b2ad2f9f4df994b0fdbbbc75b
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>