dmaengine: idxd: Fix error handling in idxd_wq_cdev_dev_setup()

We can't call kfree(dev) after calling device_register(dev).  The "dev"
pointer has to be freed using put_device().

Fixes: 42d279f ("dmaengine: idxd: add char driver to expose submission portal to userland")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Acked-by: Dave Jiang <dave.jiang@intel.com>
Link: https://lore.kernel.org/r/20200205123248.hmtog7qa2eiqaagh@kili.mountain
Signed-off-by: Vinod Koul <vkoul@kernel.org>

drivers/dma/idxd/cdev.c

@@ -204,6 +204,7 @@ static int idxd_wq_cdev_dev_setup(struct idxd_wq *wq)
 	minor = ida_simple_get(&cdev_ctx->minor_ida, 0, MINORMASK, GFP_KERNEL);
 	if (minor < 0) {
 		rc = minor;
+		kfree(dev);
 		goto ida_err;
 	}
 
@@ -212,7 +213,6 @@ static int idxd_wq_cdev_dev_setup(struct idxd_wq *wq)
 	rc = device_register(dev);
 	if (rc < 0) {
 		dev_err(&idxd->pdev->dev, "device register failed\n");
-		put_device(dev);
 		goto dev_reg_err;
 	}
 	idxd_cdev->minor = minor;
@@ -221,8 +221,8 @@ static int idxd_wq_cdev_dev_setup(struct idxd_wq *wq)
 
  dev_reg_err:
 	ida_simple_remove(&cdev_ctx->minor_ida, MINOR(dev->devt));
+	put_device(dev);
  ida_err:
-	kfree(dev);
 	idxd_cdev->dev = NULL;
 	return rc;
 }