f2fs: fix miscounted block limit in f2fs_statfs_project()

commit acdf2172 upstream.

statfs calculates Total/Used/Avail disk space in block unit,
so we should translate soft/hard prjquota limit to block unit
as well.

Below testing result shows the block/inode numbers of
Total/Used/Avail from df command are all correct afer
applying this patch.

[root@localhost quota-tools]\# ./repquota -P /dev/sdb1

fs/f2fs/super.c

@@ -1154,6 +1154,8 @@ static int f2fs_statfs_project(struct super_block *sb,
 	if (dquot->dq_dqb.dqb_bhardlimit &&
 			(!limit || dquot->dq_dqb.dqb_bhardlimit < limit))
 		limit = dquot->dq_dqb.dqb_bhardlimit;
+	if (limit)
+		limit >>= sb->s_blocksize_bits;
 
 	if (limit && buf->f_blocks > limit) {
 		curblock = dquot->dq_dqb.dqb_curspace >> sb->s_blocksize_bits;