mkfs.vfat: fix volume label to be padded with space

The specification requires volume label to be space padded.

Latest fsck.vfat will remove the zero padded volume label
as invalid. See also:
https://github.com/dosfstools/dosfstools/issues/172

Make the default label also "NO NAME" which has the special meaning
that label is not set.

function                                             old     new   delta
mkfs_vfat_main                                      1470    1502     +32
static.NO_NAME_11                                      -      12     +12
.rodata                                           104309  104318      +9
------------------------------------------------------------------------------
(add/remove: 1/0 grow/shrink: 2/0 up/down: 53/0)               Total: 53 bytes

Signed-off-by: Timo Teräs <timo.teras@iki.fi>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
1 file changed