Fix file descriptor leak on IncFS v1 am: 4d2d129f2b am: 2346524072 am: ce87de0d5a

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

Change-Id: I1eba213f3789f2c62a3da9ba9e808b0df1168a77
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>