ANDROID: Fix uninitialized warning in exfat2img am: 8a2d8e8953 am: 5539be2f27 am: 0f2a992a7a am: 4725270302 am: 62f8e80774

Original change: https://android-review.googlesource.com/c/platform/external/exfatprogs/+/2748866

Change-Id: If8577cc17f3c97b9ab2ccbad7ee44afe258ba79e
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>