If label is not set, the Label tag in superblock info show '(none)'.
```
[Before]
Device index: 0
Label:
Version: 1.4: member_seq
[After]
Device index: 0
Label: (none)
Version: 1.4: member_seq
```
Signed-off-by: Hongbo Li <lihongbo22@huawei.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
prt_printf(out, "Device index:\t%u\n", sb->dev_idx);
prt_printf(out, "Label:\t");
- prt_printf(out, "%.*s", (int) sizeof(sb->label), sb->label);
+ if (!strlen(sb->label))
+ prt_printf(out, "(none)");
+ else
+ prt_printf(out, "%.*s", (int) sizeof(sb->label), sb->label);
prt_newline(out);
prt_printf(out, "Version:\t");