arm/arm64: KVM: use __GFP_ZERO not memset() to get zeroed pages

Pass __GFP_ZERO to __get_free_pages() instead of calling memset()
explicitly.
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>

arch/arm/kvm/mmu.c

@@ -528,11 +528,10 @@ int kvm_alloc_stage2_pgd(struct kvm *kvm)
 		return -EINVAL;
 	}
 
-	pgd = (pgd_t *)__get_free_pages(GFP_KERNEL, S2_PGD_ORDER);
+	pgd = (pgd_t *)__get_free_pages(GFP_KERNEL | __GFP_ZERO, S2_PGD_ORDER);
 	if (!pgd)
 		return -ENOMEM;
 
-	memset(pgd, 0, PTRS_PER_S2_PGD * sizeof(pgd_t));
 	kvm_clean_pgd(pgd);
 	kvm->arch.pgd = pgd;