[Bug]: `CreateIndex` bypass DISKANN mmap constraint

[congqixia]

Is there an existing issue for this?

• [X] I have searched the existing issues

Environment

- Milvus version: a43baa0
- Deployment mode(standalone or cluster): 
- MQ type(rocksmq, pulsar or kafka):    
- SDK version(e.g. pymilvus v2.0.0rc2):
- OS(Ubuntu or CentOS): 
- CPU/Memory: 
- GPU: 
- Others:

Current Behavior

Create DiskANN with mmap enabled is allowed

Expected Behavior

An error shall be returned when create index with mmap attribute

Steps To Reproduce

No response

Milvus Log

No response

Anything else?

No response