quota: correct error number in free_dqentry()

Fix the error path in free_dqentry(), pass out the error number if the
block to free is not correct.

Fixes: 1ccd14b9c2 ("quota: Split off quota tree handling into a separate file")
Link: https://lore.kernel.org/r/20211008093821.1001186-3-yi.zhang@huawei.com
Signed-off-by: Zhang Yi <yi.zhang@huawei.com>
Cc: stable@kernel.org
Signed-off-by: Jan Kara <jack@suse.cz>

fs/quota/quota_tree.c

@@ -414,6 +414,7 @@ static int free_dqentry(struct qtree_mem_dqinfo *info, struct dquot *dquot,
 		quota_error(dquot->dq_sb, "Quota structure has offset to "
 			"other block (%u) than it should (%u)", blk,
 			(uint)(dquot->dq_off >> info->dqi_blocksize_bits));
+		ret = -EIO;
 		goto out_buf;
 	}
 	ret = read_blk(info, blk, buf);