Improve the checked way of the OSD created checking process.
This replaces the ceph status command by the ceph osd stat command.
The osdmap structure isn't needed anymore.

$ ceph status -f json | wc -c
2001
$ ceph osd stat -f json | wc -c
132
$ time ceph status -f json > /dev/null

real    0m0.563s
user    0m0.526s
sys     0m0.036s
$ time ceph osd stat -f json > /dev/null

real	0m0.457s
user	0m0.411s
sys	0m0.045s

Signed-off-by: wangxiaotong <wangxiaotong@fiberhome.com>