drivers/vfio: Enable VFIO if EEH is not supported

The existing vfio_pci_open() fails upon error returned from
vfio_spapr_pci_eeh_open(), which breaks POWER7's P5IOC2 PHB
support which this patch brings back.

The patch fixes the issue by dropping the return value of
vfio_spapr_pci_eeh_open().

Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: Gavin Shan <gwshan@linux.vnet.ibm.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
diff --git a/include/linux/vfio.h b/include/linux/vfio.h
index 224128a..d320411 100644
--- a/include/linux/vfio.h
+++ b/include/linux/vfio.h
@@ -100,15 +100,14 @@
 
 struct pci_dev;
 #ifdef CONFIG_EEH
-extern int vfio_spapr_pci_eeh_open(struct pci_dev *pdev);
+extern void vfio_spapr_pci_eeh_open(struct pci_dev *pdev);
 extern void vfio_spapr_pci_eeh_release(struct pci_dev *pdev);
 extern long vfio_spapr_iommu_eeh_ioctl(struct iommu_group *group,
 				       unsigned int cmd,
 				       unsigned long arg);
 #else
-static inline int vfio_spapr_pci_eeh_open(struct pci_dev *pdev)
+static inline void vfio_spapr_pci_eeh_open(struct pci_dev *pdev)
 {
-	return 0;
 }
 
 static inline void vfio_spapr_pci_eeh_release(struct pci_dev *pdev)