xhci: refuse loading if nousb is used

commit 1eaf35e4 upstream.

The module should fail to load.
Signed-off-by: Oliver Neukum <oneukum@suse.com>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>

drivers/usb/host/xhci.c

@@ -4891,6 +4891,10 @@ static int __init xhci_hcd_init(void)
 	BUILD_BUG_ON(sizeof(struct xhci_intr_reg) != 8*32/8);
 	/* xhci_run_regs has eight fields and embeds 128 xhci_intr_regs */
 	BUILD_BUG_ON(sizeof(struct xhci_run_regs) != (8+8*128)*32/8);
+
+	if (usb_disabled())
+		return -ENODEV;
+
 	return 0;
 unreg_pci:
 	xhci_unregister_pci();