serial_core: Unregister console in uart_remove_one_port()

If the serial port being removed is used as a console, it must also be
unregistered from the console subsystem using unregister_console().

uart_ops.release_port() will release resources (e.g. iounmap() the serial
port registers), causing a crash on subsequent kernel output if the console
is still registered.

Signed-off-by: Geert Uytterhoeven <geert+renesas@linux-m68k.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/tty/serial/serial_core.c

@@ -2676,6 +2676,12 @@ int uart_remove_one_port(struct uart_driver *drv, struct uart_port *uport)
 	if (port->tty)
 		tty_vhangup(port->tty);
 
+	/*
+	 * If the port is used as a console, unregister it
+	 */
+	if (uart_console(uport))
+		unregister_console(uport->cons);
+
 	/*
 	 * Free the port IO and memory resources, if any.
 	 */