Refactored libgptf_fuzzer am: 972a538f1e

Original change: https://android-review.googlesource.com/c/platform/external/gptfdisk/+/3019119

Change-Id: I1d924eb3cc37bd084ac9915a46833adfcac2f37c
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>