lsblk: clean up data preparation

Signed-off-by: Karel Zak <kzak@redhat.com>
libsmartcols: clean up flags

Signed-off-by: Karel Zak <kzak@redhat.com>
lsblk: remove unnecessary code

Signed-off-by: Karel Zak <kzak@redhat.com>
libsmartcols: init symbols when necessary

Signed-off-by: Karel Zak <kzak@redhat.com>