xhci: Don't enable legacy PCI interrupts if MSI is marked as broken

The xHCI platform driver calls into usb_add_hcd to register the irq for
its platform device. It does not want the xHCI generic driver to register
an interrupt for it at all.

This change is related to 52fb6125 in upstream

Change-Id: Iffcf7b29823d0c3bb5b77472606c492640fcabca
diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c
index 6084928..6e32385 100644
--- a/drivers/usb/host/xhci.c
+++ b/drivers/usb/host/xhci.c
@@ -342,7 +342,7 @@
 	 * generate interrupts.  Don't even try to enable MSI.
 	 */
 	if (xhci->quirks & XHCI_BROKEN_MSI)
-		goto legacy_irq;
+		return 0;
 
 	/* unregister the legacy interrupt */
 	if (hcd->irq)