serial: 8250: Remove duplicate ->handle_irq initialization

set_io_from_upio() already initializes ->handle_irq to
serial8250_default_handle_irq.
Signed-off-by: NPeter Hurley <peter@hurleysoftware.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/tty/serial/8250/8250_core.c

@@ -3423,8 +3423,6 @@ int __init early_serial_setup(struct uart_port *port)
 		p->serial_out = port->serial_out;
 	if (port->handle_irq)
 		p->handle_irq = port->handle_irq;
-	else
-		p->handle_irq = serial8250_default_handle_irq;
 
 	return 0;
 }