[SCSI] st: Move buffer pointer back when data could not be written.

Move buffer pointer back when data could not be written. Bug found by
Mike Christie.

Signed-off-by: Kai Mäkisara <Kai.Makisara@kolumbus.fi>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
1 file changed