Enable more compiler warnings am: 0febd3282d

Original change: https://android-review.googlesource.com/c/platform/external/f2fs-tools/+/2193534

Change-Id: Icf378b3be9df63d0f7ef283acac1a8e2849159f8
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>