dmaengine: convert to idr_alloc()

Convert to the much saner new idr interface.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Dan Williams <djbw@fb.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drivers/dma/dmaengine.c

@@ -686,18 +686,14 @@ static int get_dma_id(struct dma_device *device)
 {
 	int rc;
 
- idr_retry:
-	if (!idr_pre_get(&dma_idr, GFP_KERNEL))
-		return -ENOMEM;
 	mutex_lock(&dma_list_mutex);
-	rc = idr_get_new(&dma_idr, NULL, &device->dev_id);
-	mutex_unlock(&dma_list_mutex);
-	if (rc == -EAGAIN)
-		goto idr_retry;
-	else if (rc != 0)
-		return rc;
 
-	return 0;
+	rc = idr_alloc(&dma_idr, NULL, 0, 0, GFP_KERNEL);
+	if (rc >= 0)
+		device->dev_id = rc;
+
+	mutex_unlock(&dma_list_mutex);
+	return rc < 0 ? rc : 0;
 }
 
 /**