staging: r8188eu: remove ishighspeed from dvobj_priv

There's no need to store the usb device speed in struct dvobj_priv.
We can read the speed from struct usb_device. dvobj_priv has a pointer
to the usb_device.

Reorder one if-statement to make the code clearer.

Signed-off-by: Martin Kaiser <martin@kaiser.cx>
Link: https://lore.kernel.org/r/20220209192842.99399-1-martin@kaiser.cx


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>