iommu: fix a mistake for iommu_unregister_device_fault_handler

ascend inclusion
category: bugfix
bugzilla: NA
CVE: NA

-------------------------------------------------

Fix a mistake check for commit bd6c06e0917d
("iommu: introduce device fault report API")

Fixes: bd6c06e0917d ("iommu: introduce device fault report API")
Signed-off-by: NBixuan Cui <cuibixuan@huawei.com>
Reviewed-by: NHanjun Guo <guohanjun@huawei.com>
Signed-off-by: NYang Yingliang <yangyingliang@huawei.com>

drivers/iommu/iommu.c

@@ -982,7 +982,7 @@ int iommu_unregister_device_fault_handler(struct device *dev)
 
 	mutex_lock(&param->lock);
 	/* we cannot unregister handler if there are pending faults */
-	if (list_empty(&param->fault_param->faults)) {
+	if (!list_empty(&param->fault_param->faults)) {
 		ret = -EBUSY;
 		goto unlock;
 	}