iommu/amd: Small cleanup in mn_release()

"pasid_state->device_state" and "dev_state" are the same, but it's nicer
to use dev_state consistently.
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>

drivers/iommu/amd_iommu_v2.c

@@ -417,7 +417,7 @@ static void mn_release(struct mmu_notifier *mn, struct mm_struct *mm)
 	dev_state      = pasid_state->device_state;
 	run_inv_ctx_cb = !pasid_state->invalid;
 
-	if (run_inv_ctx_cb && pasid_state->device_state->inv_ctx_cb)
+	if (run_inv_ctx_cb && dev_state->inv_ctx_cb)
 		dev_state->inv_ctx_cb(dev_state->pdev, pasid_state->pasid);
 
 	unbind_pasid(pasid_state);