sheep: init journal file after init_disk_space()

When MD is enabled, we have to call journal_file_init() after
init_disk_space().  Otherwise, sheep cannot replay journal entries
correctly since md_disks are setup in md_init_space().

Signed-off-by: MORITA Kazutaka <morita.kazutaka@lab.ntt.co.jp>
Signed-off-by: Liu Yuan <tailai.ly@taobao.com>
fix printf format string

The correct format strings are:
 - %zd for ssize_t
 - %zu for size_t
 - %PRIu64 for uint64_t

Signed-off-by: MORITA Kazutaka <morita.kazutaka@lab.ntt.co.jp>
Signed-off-by: Liu Yuan <tailai.ly@taobao.com>