x86/access: Remove manual override of PUD/PMD in prefetch sub-test

Drop the overrides from the check_pfec_on_prefetch_pte() test now that
pre-allocating page tables will naturally have them use the same PUD and
PMD entries.

Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20211125012857.508243-19-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>