USB: serial: quatech2: remove set but not used variable 'port_priv'
Fixes gcc '-Wunused-but-set-variable' warning:
drivers/usb/serial/quatech2.c: In function 'qt2_process_read_urb':
drivers/usb/serial/quatech2.c:503:27: warning:
variable 'port_priv' set but not used [-Wunused-but-set-variable]
It not used any more after commit
2be818a116b2 ('Revert "USB: quatech2:
only write to the tty if the port is open."')
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Signed-off-by: Johan Hovold <johan@kernel.org>