s390/pci: fix bar check

BugLink: http://bugs.launchpad.net/bugs/1558624

Fix the check which bar space we should map to allow available bars only.
Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Reviewed-by: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
(cherry picked from commit c0cabadd)
Signed-off-by: Tim Gardner <tim.gardner@canonical.com>

arch/s390/pci/pci.c

@@ -270,7 +270,7 @@ void __iomem *pci_iomap_range(struct pci_dev *pdev,
 	struct zpci_dev *zdev =	to_zpci(pdev);
 	int idx;
 
-	if ((bar & 7) != bar)
+	if (!pci_resource_len(pdev, bar))
 		return NULL;
 
 	idx = zdev->bars[bar].map_idx;