KVM: MMU: change kvm_mmu_hugepage_adjust() arguments to kvm_page_fault

Pass struct kvm_page_fault to kvm_mmu_hugepage_adjust() instead of
extracting the arguments from the struct; the results are also stored
in the struct, so the callers are adjusted consequently.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>