xhci: remove unused argument from xhci_giveback_urb_in_irq()

This patch removes the "adjective" argument from xhci_giveback_urb_in_irq(),
since it is not used in the function anymore.

Signed-off-by: Xenia Ragiadakou <burzalodowa@gmail.com>
Acked-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>