tty: serial: qcom_geni_serial: Drop useless check for dev.of_node

tty: serial: qcom_geni_serial: Drop useless check for dev.of_node

With gcc 4.1.2:

    drivers/tty/serial/qcom_geni_serial.c: In function ‘qcom_geni_serial_probe’:
    drivers/tty/serial/qcom_geni_serial.c:1261: warning: ‘drv’ may be used uninitialized in this function

Indeed, if dev.of_node is NULL, drv will be used uninitialized, and
dereferenced in uart_add_one_port().  However, as this driver supports
DT only, dev.of_node will always be valid.

Hence remove the useless check for dev.of_node, killing the warning as a
side effect.

Fixes: 8a8a66a1a18a1dbd ("tty: serial: qcom_geni_serial: Add support for flow control")
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>