f2fs: recover inline xattr data in roll-forward process

Previously we do not recover inline xattr data of inode after power-cut, so
inline xattr data may be lost.
We should recover the data during the roll-forward process.

Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>