Fix -Wunused-variable compiler warning am: 810d41a774 am: 4eeda91a4a

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

Change-Id: I4071c9db1ab66e2624e09590f03327660bf6959c
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>