USB: gadget: bcm63xx_udc: remove dentry storage for debugfs file

There is no need to store the dentry pointer for a debugfs file that we
only use to remove it when the device goes away.  debugfs can do the
lookup for us instead, saving us some trouble, and making things smaller
overall.

Cc: Kevin Cernekee <cernekee@gmail.com>
Cc: Felipe Balbi <balbi@kernel.org>
Cc: bcm-kernel-feedback-list@broadcom.com
Link: https://lore.kernel.org/r/20210525171508.758365-1-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/gadget/udc/bcm63xx_udc.c

@@ -288,7 +288,6 @@ struct bcm63xx_req {
  * @ep0_req_completed: ep0 request has completed; worker has not seen it yet.
  * @ep0_reply: Pending reply from gadget driver.
  * @ep0_request: Outstanding ep0 request.
- * @debugfs_root: debugfs directory: /sys/kernel/debug/<DRV_MODULE_NAME>.
  */
 struct bcm63xx_udc {
 	spinlock_t			lock;
@@ -327,8 +326,6 @@ struct bcm63xx_udc {
 	unsigned			ep0_req_completed:1;
 	struct usb_request		*ep0_reply;
 	struct usb_request		*ep0_request;
-
-	struct dentry			*debugfs_root;
 };
 
 static const struct usb_ep_ops bcm63xx_udc_ep_ops;
@@ -2250,8 +2247,6 @@ static void bcm63xx_udc_init_debugfs(struct bcm63xx_udc *udc)
 		return;
 
 	root = debugfs_create_dir(udc->gadget.name, usb_debug_root);
-	udc->debugfs_root = root;
-
 	debugfs_create_file("usbd", 0400, root, udc, &bcm63xx_usbd_dbg_fops);
 	debugfs_create_file("iudma", 0400, root, udc, &bcm63xx_iudma_dbg_fops);
 }
@@ -2264,7 +2259,7 @@ static void bcm63xx_udc_init_debugfs(struct bcm63xx_udc *udc)
  */
 static void bcm63xx_udc_cleanup_debugfs(struct bcm63xx_udc *udc)
 {
-	debugfs_remove_recursive(udc->debugfs_root);
+	debugfs_remove(debugfs_lookup(udc->gadget.name, usb_debug_root));
 }
 
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