scsi: isci: Add a missing call to pci_unmap_biosrom

Most error branches following the call to pci_map_biosrom contain a call
to pci_unmap_biosrom. This patch add these calls where they are missing.

This issue was found with Hector.
Signed-off-by: Quentin Lambert <lambert.quentin@gmail.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

drivers/scsi/isci/probe_roms.c

@@ -54,6 +54,7 @@ struct isci_orom *isci_request_oprom(struct pci_dev *pdev)
 	len = pci_biosrom_size(pdev);
 	rom = devm_kzalloc(&pdev->dev, sizeof(*rom), GFP_KERNEL);
 	if (!rom) {
+		pci_unmap_biosrom(oprom);
 		dev_warn(&pdev->dev,
 			 "Unable to allocate memory for orom\n");
 		return NULL;