USB: FHCI: use the new usb debugfs directory

All usb debugfs files should be behind the usb directory, not at the
root of debugfs.

Signed-off-by: Greg Kroah-Hartman <[e-mail]>

drivers/usb/host/fhci-dbg.c

···
 {
 	struct device *dev = fhci_to_hcd(fhci)->self.controller;
 
-	fhci->dfs_root = debugfs_create_dir(dev_name(dev), NULL);
+	fhci->dfs_root = debugfs_create_dir(dev_name(dev), usb_debug_root);
 	if (!fhci->dfs_root) {
 		WARN_ON(1);
 		return;