KVM: x86/mmu: Remove redundant role overrides for TDP MMU shadow pages

The vCPU's mmu_role already has the correct values for direct,
has_4_byte_gpte, access, and ad_disabled. Remove the code that was
redundantly overwriting these fields with the same values.

No functional change intended.

Suggested-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: David Matlack <dmatlack@google.com>
Message-Id: <20220119230739.2234394-13-dmatlack@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>