scsi_remove_host() sends SYNCHRONIZE CACHE commands for write cache
enabled scsi disk devices.  So stopping controller working shouldn't
be done before scsi_remove_host().
Signed-off-by: Akinobu Mita <mita@fixstars.com>
Signed-off-by: Santosh Y <santoshsy@gmail.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>