applypatch: Release FD when explicitly calling close.

We use android::base::unique_fd() to avoid leaking FD. We also want to
call close (or ota_close) to explicitly check the close result. When
combining the two together, we need to release the unique_fd to avoid
closing the same FD twice.

Bug: 33034669
Test: Trigger applypatch with install-recovery.sh.
Change-Id: I1a4f5d5fba7a23ef98d8bd7b7b07e87ae6f705c5