scsi: inline sg_io_sense_from_errno() into the callers.

Currently sg_io_sense_from_errno() converts the two input parameters
'errno' and 'io_hdr' into sense code and SCSI status. Having
split the function off into scsi_sense_from_errno() and
scsi_sense_from_host_status(), both of which are available generically,
we now inline the logic in the callers so that scsi-disk and
scsi-generic will be able to pass host_status to the HBA.

Signed-off-by: Hannes Reinecke <hare@suse.de>
Message-Id: <20201116184041.60465-7-hare@suse.de>
[Put together from "scsi-disk: Add sg_io callback to evaluate status"
 and what remains of "scsi: split sg_io_sense_from_errno() in two functions",
 with many other fixes. - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>