c5f52875 changed the size of sense array in vmstate_scsi_device by
mistake. This patch restores the old size, and add a subsection for the
remaining part of the buffer size. So that migration is not broken.
Signed-off-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>