Earlier PTR_ERR was being returned even if group was set to null.
Now, we explicitly set an ERR_PTR value in case the group  pointer is
NULL.
Signed-off-by: Varun Sethi <Varun.Sethi@freescale.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
                        group = get_shared_pci_device_group(pdev);
        }
 
+       if (!group)
+               group = ERR_PTR(-ENODEV);
+
        return group;
 }
 
 static int fsl_pamu_add_device(struct device *dev)
 {
-       struct iommu_group *group = NULL;
+       struct iommu_group *group = ERR_PTR(-ENODEV);
        struct pci_dev *pdev;
        const u32 *prop;
        int ret, len;
                        group = get_device_iommu_group(dev);
        }
 
-       if (!group || IS_ERR(group))
+       if (IS_ERR(group))
                return PTR_ERR(group);
 
        ret = iommu_group_add_device(group, dev);