USB: fotg210-hcd: 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.

Link: https://lore.kernel.org/r/20210525172534.848775-1-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/host/fotg210-hcd.c

@@ -850,7 +850,6 @@ static inline void create_debug_files(struct fotg210_hcd *fotg210)
 	struct dentry *root;
 
 	root = debugfs_create_dir(bus->bus_name, fotg210_debug_root);
-	fotg210->debug_dir = root;
 
 	debugfs_create_file("async", S_IRUGO, root, bus, &debug_async_fops);
 	debugfs_create_file("periodic", S_IRUGO, root, bus,
@@ -861,7 +860,9 @@ static inline void create_debug_files(struct fotg210_hcd *fotg210)
 
 static inline void remove_debug_files(struct fotg210_hcd *fotg210)
 {
-	debugfs_remove_recursive(fotg210->debug_dir);
+	struct usb_bus *bus = &fotg210_to_hcd(fotg210)->self;
+
+	debugfs_remove(debugfs_lookup(bus->bus_name, fotg210_debug_root));
 }
 
 /* handshake - spin reading hc until handshake completes or fails

drivers/usb/host/fotg210.h

@@ -184,9 +184,6 @@ struct fotg210_hcd {			/* one per controller */
 
 	/* silicon clock */
 	struct clk		*pclk;
-
-	/* debug files */
-	struct dentry		*debug_dir;
 };
 
 /* convert between an HCD pointer and the corresponding FOTG210_HCD */