USB: host: isp1362: 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: [e-mail]
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Greg Kroah-Hartman <[e-mail]>

drivers/usb/host/isp1362-hcd.c

···
 /* expect just one isp1362_hcd per system */
 static void create_debug_file(struct isp1362_hcd *isp1362_hcd)
 {
-	isp1362_hcd->debug_file = debugfs_create_file("isp1362", S_IRUGO,
-						      usb_debug_root,
-						      isp1362_hcd,
-						      &isp1362_fops);
+	debugfs_create_file("isp1362", S_IRUGO, usb_debug_root, isp1362_hcd,
+			    &isp1362_fops);
 }
 
 static void remove_debug_file(struct isp1362_hcd *isp1362_hcd)
 {
-	debugfs_remove(isp1362_hcd->debug_file);
+	debugfs_remove(debugfs_lookup("isp1362", usb_debug_root));
 }
 
 /*-------------------------------------------------------------------------*/

drivers/usb/host/isp1362.h

···
 
 	struct isp1362_platform_data *board;
 
-	struct dentry		*debug_file;
 	unsigned long		stat1, stat2, stat4, stat8, stat16;
 
 	/* HC registers */