Reuse the same object alloc QoS code as LOD, but the QoS code is
not moved to lower layer module, instead it's copied to LMV, because
it involves almost all LMV code, which is too big a change and should
be done separately in the future.

And for LMV round-robin object allocation, because we only need to
allocate one object, use the MDT index saved and update it to next
MDT.

Add sanity 413b.

Signed-off-by: Lai Siyao <lai.siyao@whamcloud.com>
Change-Id: I53c3d863dafda534eebb6b95da205b395071cd25
Reviewed-on: https://review.whamcloud.com/34657


Tested-by: Jenkins
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: Hongchao Zhang <hongchao@whamcloud.com>
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>