LU-11115 lod: skip max_create_count=0 OST in QoS and RR algorithms

LU-11115 lod: skip max_create_count=0 OST in QoS and RR algorithms

While choosing OST to create object, both lod_alloc_qos() and
lod_alloc_rr() functions use lod_statfs_and_check() function
to check whether the OST is available for new OST objects or not.
However, OST with max_create_count=0 is not checked in that
function and just returned as an available OST.

This patch fixes the above issue by detecting OST with
max_create_count=0 in lod_statfs_and_check() and skip it.

Change-Id: Ic2129b483ead16f8971a062e326d5ecd537b7e6c
Signed-off-by: Jian Yu <yujian@whamcloud.com>
Reviewed-on: https://review.whamcloud.com/32859
Tested-by: Jenkins
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>
Reviewed-by: John L. Hammond <jhammond@whamcloud.com>