f2fs: fix to recover inode->i_flags of inode block during POR

Testcase to reproduce this bug:
1. mkfs.f2fs /dev/sdd
2. mount -t f2fs /dev/sdd /mnt/f2fs
3. touch /mnt/f2fs/file
4. sync
5. chattr +a /mnt/f2fs/file
6. xfs_io -a /mnt/f2fs/file -c "fsync"
7. godown /mnt/f2fs
8. umount /mnt/f2fs
9. mount -t f2fs /dev/sdd /mnt/f2fs
10. xfs_io /mnt/f2fs/file

There is no error when opening this file w/o O_APPEND, but actually,
we expect the correct result should be:

/mnt/f2fs/file: Operation not permitted

The root cause is, in recover_inode(), we recover inode->i_flags more
than F2FS_I(inode)->i_flags, so fix it.
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

fs/f2fs/recovery.c

@@ -234,6 +234,7 @@ static void recover_inode(struct inode *inode, struct page *page)
 
 	F2FS_I(inode)->i_advise = raw->i_advise;
 	F2FS_I(inode)->i_flags = le32_to_cpu(raw->i_flags);
+	f2fs_set_inode_flags(inode);
 	F2FS_I(inode)->i_gc_failures[GC_FAILURE_PIN] =
 				le16_to_cpu(raw->i_gc_failures);