KVM: MMU: abstract the operation of rmap

Abstract the operation of rmap to spte_list, then we can use it for the
reverse mapping of parent pte in the later patch

Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 387780e..e6a4a57 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -347,7 +347,7 @@
 	struct kvm_pv_mmu_op_buffer mmu_op_buffer;
 
 	struct kvm_mmu_memory_cache mmu_pte_chain_cache;
-	struct kvm_mmu_memory_cache mmu_rmap_desc_cache;
+	struct kvm_mmu_memory_cache mmu_pte_list_desc_cache;
 	struct kvm_mmu_memory_cache mmu_page_cache;
 	struct kvm_mmu_memory_cache mmu_page_header_cache;