usb/uhci: initialize sg_table properly

Commit 689d6eac ("USB: UHCI: add native scatter-gather support(v1))
added sg support to uhci but forgot to set the sg_table so this feature
remained unused.

Cc: Ming Lei <tom.leiming@gmail.com>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/usb/host/uhci-hcd.c

@@ -565,6 +565,9 @@ static int uhci_start(struct usb_hcd *hcd)
 	struct dentry __maybe_unused *dentry;
 
 	hcd->uses_new_polling = 1;
+	/* Accept arbitrarily long scatter-gather lists */
+	if (!(hcd->driver->flags & HCD_LOCAL_MEM))
+		hcd->self.sg_tablesize = ~0;
 
 	spin_lock_init(&uhci->lock);
 	setup_timer(&uhci->fsbr_timer, uhci_fsbr_timeout,