usb: gadget: udc: renesas_usb3: should remove debugfs

This patch fixes an issue that this driver doesn't remove its debugfs.

Fixes: 43ba968b ("usb: gadget: udc: renesas_usb3: add debugfs to set the b-device mode")
Cc: <stable@vger.kernel.org> # v4.14+
Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Reviewed-by: Simon Horman <horms+renesas@verge.net.au>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>

drivers/usb/gadget/udc/renesas_usb3.c

@@ -333,6 +333,7 @@ struct renesas_usb3 {
 	struct extcon_dev *extcon;
 	struct work_struct extcon_work;
 	struct phy *phy;
+	struct dentry *dentry;
 
 	struct renesas_usb3_ep *usb3_ep;
 	int num_usb3_eps;
@@ -2393,8 +2394,12 @@ static void renesas_usb3_debugfs_init(struct renesas_usb3 *usb3,
 
 	file = debugfs_create_file("b_device", 0644, root, usb3,
 				   &renesas_usb3_b_device_fops);
-	if (!file)
+	if (!file) {
 		dev_info(dev, "%s: Can't create debugfs mode\n", __func__);
+		debugfs_remove_recursive(root);
+	} else {
+		usb3->dentry = root;
+	}
 }
 
 /*------- platform_driver ------------------------------------------------*/
@@ -2402,6 +2407,7 @@ static int renesas_usb3_remove(struct platform_device *pdev)
 {
 	struct renesas_usb3 *usb3 = platform_get_drvdata(pdev);
 
+	debugfs_remove_recursive(usb3->dentry);
 	device_remove_file(&pdev->dev, &dev_attr_role);
 
 	usb_del_gadget_udc(&usb3->gadget);