usb: xhci: fix Immediate Data Transfer endianness

The arguments to queue_trb are always byteswapped to LE for placement in
the ring, but this should not happen in the case of immediate data; the
bytes copied out of transfer_buffer are already in the correct order.
Add a complementary byteswap so the bytes end up in the ring correctly.

This was observed on BE ppc64 with a "Texas Instruments TUSB73x0
SuperSpeed USB 3.0 xHCI Host Controller [104c:8241]" as a ch341
usb-serial adapter ("1a86:7523 QinHeng Electronics HL-340 USB-Serial
adapter") always transmitting the same character (generally NUL) over
the serial link regardless of the key pressed.

Cc: <stable@vger.kernel.org> # 5.2+
Fixes: 33e39350

 ("usb: xhci: add Immediate Data Transfer support")
Signed-off-by: Samuel Holland <samuel@sholland.org>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Link: https://lore.kernel.org/r/1572013829-14044-3-git-send-email-mathias.nyman@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>