Enable running in fsdax mode

[kelvin-qin]

Now Spark pmem-shuffle doesn't work in pmem's FSDAX mode.
This should be optional, and users should have the option to run on FSDAX when they are not using RDMA NIC(RDMA is too complex to use).
Therefore, it is necessary to make appropriate modifications to the code to run in FSDAX mode.

[kelvin-qin]

ok.