Fix -Wunused-variable compiler warning am: 810d41a7 am: 4eeda91a am: 76705af8

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



Change-Id: I00242599f1a67f59a8e2f415ffa52231d54007dc
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>