KVM: MMU: Remove some useless code from alloc_mmu_pages()

If we fail to alloc page for vcpu->arch.mmu.pae_root, call to
free_mmu_pages() is unnecessary, which just do free the page
malloc for vcpu->arch.mmu.pae_root.
Signed-off-by: Wei Yongjun <yjwei@cn.fujitsu.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>

arch/x86/kvm/mmu.c

@@ -2843,16 +2843,13 @@ static int alloc_mmu_pages(struct kvm_vcpu *vcpu)
 	 */
 	page = alloc_page(GFP_KERNEL | __GFP_DMA32);
 	if (!page)
-		goto error_1;
+		return -ENOMEM;
+
 	vcpu->arch.mmu.pae_root = page_address(page);
 	for (i = 0; i < 4; ++i)
 		vcpu->arch.mmu.pae_root[i] = INVALID_PAGE;
 
 	return 0;
-
-error_1:
-	free_mmu_pages(vcpu);
-	return -ENOMEM;
 }
 
 int kvm_mmu_create(struct kvm_vcpu *vcpu)