userfaultfd: don't use unsupported feature am: 4a3ec628c0

Original change: https://android-review.googlesource.com/c/platform/external/linux-kselftest/+/2169802

Change-Id: I74c579a9cc598988bc397162b6e4051fc94bcf4f
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>