usb: host: xhci: remove typo in function documentation

Fix "though" to "through" in documentation of xhci_alloc_streams().
Signed-off-by: Luis de Bethencourt <luis@debethencourt.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/host/xhci.c

@@ -3117,7 +3117,7 @@ static u32 xhci_calculate_no_streams_bitmask(struct xhci_hcd *xhci,
 }
 
 /*
- * The USB device drivers use this function (though the HCD interface in USB
+ * The USB device drivers use this function (through the HCD interface in USB
  * core) to prepare a set of bulk endpoints to use streams.  Streams are used to
  * coordinate mass storage command queueing across multiple endpoints (basically
  * a stream ID == a task ID).