USB: fhci-hcd: no need to check return value of debugfs_create functions

When calling debugfs functions, there is no need to ever check the
return value. The function can work or not, but the code logic should
never do something different based on this.

There is also no need to keep the file dentries around at all, so remove
those variables from the host controller structure.

Cc: Felipe Balbi <[e-mail]>
Cc: Andy Shevchenko <[e-mail]>
Cc: Johan Hovold <[e-mail]>
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), usb_debug_root);
-	if (!fhci->dfs_root) {
-		WARN_ON(1);
-		return;
-	}
 
-	fhci->dfs_regs = debugfs_create_file("regs", S_IFREG | S_IRUGO,
-		fhci->dfs_root, fhci, &fhci_dfs_regs_fops);
-
-	fhci->dfs_irq_stat = debugfs_create_file("irq_stat",
-		S_IFREG | S_IRUGO, fhci->dfs_root, fhci,
-		&fhci_dfs_irq_stat_fops);
-
-	WARN_ON(!fhci->dfs_regs || !fhci->dfs_irq_stat);
+	debugfs_create_file("regs", S_IFREG | S_IRUGO, fhci->dfs_root, fhci,
+			    &fhci_dfs_regs_fops);
+	debugfs_create_file("irq_stat", S_IFREG | S_IRUGO, fhci->dfs_root, fhci,
+			    &fhci_dfs_irq_stat_fops);
 }
 
 void fhci_dfs_destroy(struct fhci_hcd *fhci)
 {
-	if (!fhci->dfs_root)
-		return;
-
-	debugfs_remove(fhci->dfs_irq_stat);
-	debugfs_remove(fhci->dfs_regs);
-	debugfs_remove(fhci->dfs_root);
+	debugfs_remove_recursive(fhci->dfs_root);
 }

drivers/usb/host/fhci.h

···
 #ifdef CONFIG_FHCI_DEBUG
 	int usb_irq_stat[13];
 	struct dentry *dfs_root;
-	struct dentry *dfs_regs;
-	struct dentry *dfs_irq_stat;
 #endif
 };