Fix file descriptor leak on IncFS v1 am: 4d2d129f2b am: 2346524072

Original change: https://android-review.googlesource.com/c/platform/system/incremental_delivery/+/2289234

Change-Id: I682a4acc3362ee666191f39a5cbfd55a8611cd0e
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>