scsi: Fix SCSI bus reset When the controller raises the SCSI reset line, we have to perform the requested reset on all disks attached to the controller's bus. Moreover, reset is edge triggered, so avoid repeating it if the line was already high. Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com> Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>