[PATCH 06/10] xfstests: fix generic/225 to check fiemap support

[Junho Ryu]

>> I'd just rename if _require_fiemap, because we need both xfs_io and
>> kernel support for it, and we need xfs_io support to check for
>> kernel support....
>
> Fine with me.

There are 3 more _require_xfs_io_.* functions. I can create another
patch if you want these names to be consistent.

_require_xfs_io_falloc()
_require_xfs_io_falloc_punch()
_require_xfs_io_zero()