Fix XFS 'ftype' option typo
Fix XFS 'ftype' option typo

The required XFS option is called ftype, not fstype:

```
xfs_info / | grep ftype
naming   =version 2              bsize=4096   ascii-ci=0 ftype=1
```
thaJeztah/docker.github.io,docker/docker.github.io,londoncalling/docker.github.io,londoncalling/docker.github.io,londoncalling/docker.github.io,docker/docker.github.io,docker/docker.github.io,thaJeztah/docker.github.io,docker/docker.github.io,londoncalling/docker.github.io,thaJeztah/docker.github.io,londoncalling/docker.github.io,docker/docker.github.io,thaJeztah/docker.github.io,thaJeztah/docker.github.io