fsck.f2fs: fix wrong addrs_per_{inode,block}

fsck.f2fs: fix wrong addrs_per_{inode,block}

generic/339 reports below assertion on image w/ compression feature
enabled.

[ASSERT] (f2fs_check_dirent_position:1366)  -->
Wrong position of dirent pino:4521, name:"....", level:9, dir_level:0,
pgofs:1880, correct range:[1882, 1883]

The root cause is we calculate blkaddr number in direct node
incorrectly for directory inode, since during calculation, we only
need align blkaddr number to cluster size for regular inode rather
than directory inode, let's fix it.

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>