iommu: Fix NULL pointer bug

hulk inclusion
category: feature
bugzilla: 14369
CVE: NA
-------------------

while acpi dev set error, the iommu_fwspec can become NULL,
so, when group be abnormal, return errno.
Signed-off-by: NJiankang Chen <chenjiankang1@huawei.com>
Signed-off-by: NFang Lijun <fanglijun3@huawei.com>
Reviewed-by: NHanjun Guo <guohanjun@huawei.com>
Reviewed-by: NZhen Lei <thunder.leizhen@huawei.com>
Signed-off-by: NYang Yingliang <yangyingliang@huawei.com>

drivers/iommu/arm-smmu-v3.c

@@ -2925,24 +2925,19 @@ static int arm_smmu_add_device(struct device *dev)
 	if (ret)
 		goto err_disable_ats;
 
-	ret = arm_smmu_insert_master(smmu, master);
-	if (ret)
-		goto err_unlink;
-
 	group = iommu_group_get_for_dev(dev);
 	if (IS_ERR(group)) {
 		ret = PTR_ERR(group);
 		goto err_remove_master;
 	}
 
+	arm_smmu_insert_master(smmu, master);
 	iommu_group_put(group);
 
 	return 0;
 
 err_remove_master:
 	arm_smmu_remove_master(smmu, master);
-
-err_unlink:
 	iommu_device_unlink(&smmu->iommu, dev);
 
 err_disable_ats: