Fix -Wunused-variable compiler warning am: 810d41a774 am: c10d57af29 am: 9eb2debc5e

Original change: https://android-review.googlesource.com/c/platform/hardware/interfaces/+/2861356

Change-Id: Id397ec4574461bb963fe21d4e8ccee169a6d89cd
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>