usb: core: Remove duplicated check in usb_hub_create_port_device

Simplify the code by not calling hub_is_superspeed() twice.

Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Link: https://lore.kernel.org/r/b1d77cbc-faa3-4d07-94ff-f6ffb85c6964@gmail.com


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