FROMLIST: scsi: core: Retry passthrough commands if SCMD_RETRY_PASSTHROUGH is set

The SCSI core does not retry passthrough commands even if the SCSI device
reports a retryable unit attention condition. Support retrying in this case
by introducing the SCMD_RETRY_PASSTHROUGH flag.

Cc: Damien Le Moal <dlemoal@kernel.org>
Cc: Mike Christie <michael.christie@oracle.com>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Bart Van Assche <bvanassche@google.com>
Bug: 348341595
Link: https://lore.kernel.org/linux-scsi/yq17ccp1i4b.fsf@ca-mkp.ca.oracle.com/T/#mfdb1a3a0d6d4803afe1098bdafc12fd4168e30e0


Change-Id: I44092a0d8853fd61bf619e5bae6d65eaaddad780
Signed-off-by: Bart Van Assche <bvanassche@google.com>