generic/066: attr1 is still there after log replay on f2fs

generic/066: attr1 is still there after log replay on f2fs

The test fail on f2fs:
     xattr names and values after second fsync log replay:
     # file: SCRATCH_MNT/foobar
    +user.attr1="val1"
     user.attr3="val3"

attr1 is still there after log replay. f2fs doesn't support fs-op level
transaction functionality. so it have no way to persist all metadata
updates in one transaction.  We can use "fastboot" mountoption for this
case, so during last fsync on qwerty, f2fs can trigger a checkpoint
which will persist all metadata updates before fsync().

Suggested-by: Chao Yu <chao@kernel.org>
Signed-off-by: Sun Ke <sunke32@huawei.com>
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Eryu Guan <guaneryu@gmail.com>