x86, xen: Use native_pte_flags instead of native_pte_val for .pte_flags

Using native_pte_val triggers the BUG_ON() in the paravirt_ops
version of pte_flags().
Signed-off-by: NEduardo Habkost <ehabkost@redhat.com>
Acked-by: NJeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

arch/x86/xen/enlighten.c

@@ -1347,7 +1347,7 @@ static const struct pv_mmu_ops xen_mmu_ops __initdata = {
 	.ptep_modify_prot_commit = __ptep_modify_prot_commit,
 
 	.pte_val = xen_pte_val,
-	.pte_flags = native_pte_val,
+	.pte_flags = native_pte_flags,
 	.pgd_val = xen_pgd_val,
 
 	.make_pte = xen_make_pte,