KVM: arm64: Remove unused 'pgd' field from 'struct kvm_s2_mmu'

The stage-2 page-tables are entirely encapsulated by the 'pgt' field of
'struct kvm_s2_mmu', so remove the unused 'pgd' field.
Signed-off-by: Will Deacon <will@kernel.org>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Reviewed-by: Gavin Shan <gshan@redhat.com>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Quentin Perret <qperret@google.com>
Link: https://lore.kernel.org/r/20200911132529.19844-21-will@kernel.org

arch/arm64/include/asm/kvm_host.h

@@ -79,7 +79,6 @@ struct kvm_s2_mmu {
 	 * for vEL1/EL0 with vHCR_EL2.VM == 0.  In that case, we use the
 	 * canonical stage-2 page tables.
 	 */
-	pgd_t		*pgd;
 	phys_addr_t	pgd_phys;
 	struct kvm_pgtable *pgt;
 

arch/arm64/kvm/mmu.c

@@ -389,7 +389,6 @@ int kvm_init_stage2_mmu(struct kvm *kvm, struct kvm_s2_mmu *mmu)
 	mmu->kvm = kvm;
 	mmu->pgt = pgt;
 	mmu->pgd_phys = __pa(pgt->pgd);
-	mmu->pgd = (void *)pgt->pgd;
 	mmu->vmid.vmid_gen = 0;
 	return 0;
 
@@ -475,7 +474,6 @@ void kvm_free_stage2_pgd(struct kvm_s2_mmu *mmu)
 	spin_lock(&kvm->mmu_lock);
 	pgt = mmu->pgt;
 	if (pgt) {
-		mmu->pgd = NULL;
 		mmu->pgd_phys = 0;
 		mmu->pgt = NULL;
 		free_percpu(mmu->last_vcpu_ran);