ceph_cephfs resource tries to mount again (mons order changed)

I currently have the following mounted fs in my fstab:

```
1.2.3.1:6789,1.2.3.3:6789,1.2.3.4:6789,1.2.3.2:6789:/ /media/ceph ceph _netdev,name=cephfs.mymachine,secretfile=/etc/ceph/ceph.client.cephfs.mymachine.secret 0 0
```

chef-client tries to mount the "new" fs and mount exits unsuccessfuly:

```
[2014-12-03T14:50:19-05:00] ERROR: mount[mount /media/ceph] (/var/chef/cache/cookbooks/ceph/providers/cephfs.rb line 35) had an error: Mixlib::ShellOut::ShellCommandFailed: Expected process to exit with [0], but received '16'
---- Begin output of mount -t ceph -o _netdev,name=cephfs.mymachine,secretfile=/etc/ceph/ceph.client.cephfs.mymachine.secret 1.2.3.1:6789,1.2.3.4:6789,1.2.3.3:6789,1.2.3.2:6789:/ /media/ceph ----
STDOUT: mount error 16 = Device or resource busy
STDERR:
---- End output of mount -t ceph -o _netdev,name=cephfs.mymachine,secretfile=/etc/ceph/ceph.client.cephfs.mymachine.secret 1.2.3.1:6789,1.2.3.4:6789,1.2.3.3:6789,1.2.3.2:6789:/ /media/ceph ----
Ran mount -t ceph -o _netdev,name=cephfs.mymachine,secretfile=/etc/ceph/ceph.client.cephfs.mymachine.secret 1.2.3.1:6789,1.2.3.4:6789,1.2.3.3:6789,1.2.3.2:6789:/ /media/ceph returned 16
[2014-12-03T14:50:19-05:00] FATAL: Chef::Exceptions::ChildConvergeError: Chef run process exited unsuccessfully (exit code 1)
```

It seems that the order of mons is not kept between runs. (1,3,4,2 vs 1,4,3,2)