Upgrade userfaultfd-sys to 0.4.3 am: 29d0edf47f am: 5c1a5fca96 am: c05a4277a0 am: 908d923cde

Original change: https://android-review.googlesource.com/c/platform/external/rust/crates/userfaultfd-sys/+/2515095

Change-Id: I231b5b050d60eb77acfa0fbda1932d6e4c1c6225
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>