USB: host: isp116x: remove dentry pointer for debugfs

There is no need to keep the dentry pointer around for the created
debugfs file, as it is only needed when removing it from the system.
When it is to be removed, ask debugfs itself for the pointer, to save on
storage and make things a bit simpler.

Cc: Olav Kongas <ok@artecdesign.ee>
Cc: linux-usb@vger.kernel.org
Link: https://lore.kernel.org/r/20210216144645.3813043-1-gregkh@linuxfoundation.orgSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/host/isp116x-hcd.c

@@ -1200,14 +1200,13 @@ DEFINE_SHOW_ATTRIBUTE(isp116x_debug);
 
 static void create_debug_file(struct isp116x *isp116x)
 {
-	isp116x->dentry = debugfs_create_file(hcd_name,
-					      S_IRUGO, NULL, isp116x,
-					      &isp116x_debug_fops);
+	debugfs_create_file(hcd_name, S_IRUGO, usb_debug_root, isp116x,
+			    &isp116x_debug_fops);
 }
 
 static void remove_debug_file(struct isp116x *isp116x)
 {
-	debugfs_remove(isp116x->dentry);
+	debugfs_remove(debugfs_lookup(hcd_name, usb_debug_root));
 }
 
 #else

drivers/usb/host/isp116x.h

@@ -260,7 +260,6 @@ struct isp116x {
 
 	struct isp116x_platform_data *board;
 
-	struct dentry *dentry;
 	unsigned long stat1, stat2, stat4, stat8, stat16;
 
 	/* HC registers */