usb: xhci: remove unnecessary return in xhci_pci_setup()

Remove the unnecessary return line in xhci_pci_setup().

Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>