isci: allow fallback to option-rom if efi variable retrieval fails

If the scu efi driver is disabled but the option-rom is enabled (during an efi
boot) allow the code to fallback to scanning legacy option-rom space for the
parameters.
Reported-by: NYinghai Lu <yinghai.lu@oracle.com>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

drivers/scsi/isci/init.c

@@ -475,7 +475,7 @@ static int __devinit isci_pci_probe(struct pci_dev *pdev, const struct pci_devic
 	int err, i;
 	struct isci_host *isci_host;
 	const struct firmware *fw = NULL;
-	struct isci_orom *orom;
+	struct isci_orom *orom = NULL;
 	char *source = "(platform)";
 
 	check_si_rev(pdev);
@@ -487,7 +487,8 @@ static int __devinit isci_pci_probe(struct pci_dev *pdev, const struct pci_devic
 
 	if (efi_enabled)
 		orom = isci_get_efi_var(pdev);
-	else
+
+	if (!orom)
 		orom = isci_request_oprom(pdev);
 
 	for (i = 0; orom && i < ARRAY_SIZE(orom->ctrl); i++) {