KVM: Fix some out-dated function names in comment

Since commit b1346ab2 ("KVM: nVMX: Rename prepare_vmcs02_*_full to
prepare_vmcs02_*_rare"), prepare_vmcs02_full has been renamed to
prepare_vmcs02_rare.
nested_vmx_merge_msr_bitmap is renamed to nested_vmx_prepare_msr_bitmap
since commit c992384b ("KVM: vmx: speed up MSR bitmap merge").
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

arch/x86/kvm/vmx/vmcs_shadow_fields.h

@@ -23,7 +23,7 @@ BUILD_BUG_ON(1)
  *
  * When adding or removing fields here, note that shadowed
  * fields must always be synced by prepare_vmcs02, not just
- * prepare_vmcs02_full.
+ * prepare_vmcs02_rare.
  */
 
 /*

arch/x86/kvm/vmx/vmx.c

@@ -2008,7 +2008,7 @@ static int vmx_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
 		 *
 		 * For nested:
 		 * The handling of the MSR bitmap for L2 guests is done in
-		 * nested_vmx_merge_msr_bitmap. We should not touch the
+		 * nested_vmx_prepare_msr_bitmap. We should not touch the
 		 * vmcs02.msr_bitmap here since it gets completely overwritten
 		 * in the merging. We update the vmcs01 here for L1 as well
 		 * since it will end up touching the MSR anyway now.
@@ -2044,7 +2044,7 @@ static int vmx_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
 		 *
 		 * For nested:
 		 * The handling of the MSR bitmap for L2 guests is done in
-		 * nested_vmx_merge_msr_bitmap. We should not touch the
+		 * nested_vmx_prepare_msr_bitmap. We should not touch the
 		 * vmcs02.msr_bitmap here since it gets completely overwritten
 		 * in the merging.
 		 */