exFAT superblock not probed

[lethean]

After commit 37f4060225df0591ab8e1dd676dbc8115d900d4f, exFAT filesystem is not probed by blkid.

commit 37f4060225df0591ab8e1dd676dbc8115d900d4f
Author: Hannes Reinecke <hare@suse.de>
Date:   Thu Mar 20 11:03:50 2014 +0100

    blkid: convert superblocks to new calling convention

    With the previous patch the scanning functions were
    modified to return a differentiated return code.
    To correctly abort scanning when an I/O error occurs
    we need to differentiate between 'error' (= -1) and
    'not found' (= 1) in the probe functions.
    This patch updates all superblock scanning functions
    to the new calling convention.

    Signed-off-by: Hannes Reinecke <hare@suse.de>
    Signed-off-by: Karel Zak <kzak@redhat.com>

When I revert some code, it probes exFAT disk properly like:

$ blkid
/dev/sdd1: UUID="3402-0CBC" TYPE="exfat" PARTUUID="be580595-01" 

Following is my patch.

From 68dec3b54fc1538a0048caf8cc2df9d4f9ae07b1 Mon Sep 17 00:00:00 2001
From: Sunjin Yang <fan4326@gmail.com>
Date: Fri, 5 Sep 2014 14:32:26 +0900
Subject: [PATCH] blkid: fix exFAT superblock not probed

---
 libblkid/src/superblocks/exfat.c | 2 --
 1 file changed, 2 deletions(-)

diff --git a/libblkid/src/superblocks/exfat.c b/libblkid/src/superblocks/exfat.c
index b526560..b1173b8 100644
--- a/libblkid/src/superblocks/exfat.c
+++ b/libblkid/src/superblocks/exfat.c
@@ -121,8 +121,6 @@ static int probe_exfat(blkid_probe pr, const struct blkid_idmag *mag)
    if (label)
        blkid_probe_set_utf8label(pr, label->name,
                min(label->length * 2, 30), BLKID_ENC_UTF16LE);
-   else if (errno)
-       return -errno;

    blkid_probe_sprintf_uuid(pr, sb->volume_serial, 4,
            "%02hhX%02hhX-%02hhX%02hhX",
-- 
2.1.0

I don't know that this is a correct patch, but it works.

Any suggestion or idea?