iommu/amd: Use wait_event in put_pasid_state_wait

Now that I learned about possible spurious wakeups this
place needs fixing too. Replace the self-coded sleep variant
with the generic wait_event() helper.

Signed-off-by: Joerg Roedel <jroedel@suse.de>

drivers/iommu/amd_iommu_v2.c

@@ -266,14 +266,7 @@ static void put_pasid_state(struct pasid_state *pasid_state)
 
 static void put_pasid_state_wait(struct pasid_state *pasid_state)
 {
-	DEFINE_WAIT(wait);
+	wait_event(pasid_state->wq, !atomic_read(&pasid_state->count));
-
-	prepare_to_wait(&pasid_state->wq, &wait, TASK_UNINTERRUPTIBLE);
-
-	if (!atomic_dec_and_test(&pasid_state->count))
-		schedule();
-
-	finish_wait(&pasid_state->wq, &wait);
 	free_pasid_state(pasid_state);
 }