serial: arc: Remove __init marking from early write

The earlycon would be alive outside the init code in these cases:
1/ we have keep_bootcon in cmdline.
2/ we don't have a real console to switch to.

So remove the __init marking to avoid invalid memory access.
Signed-off-by: Jeffy Chen <jeffy.chen@rock-chips.com>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Tested-by: Brian Norris <briannorris@chromium.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/tty/serial/arc_uart.c

@@ -549,8 +549,8 @@ static struct console arc_console = {
 	.data	= &arc_uart_driver
 };
 
-static __init void arc_early_serial_write(struct console *con, const char *s,
-					  unsigned int n)
+static void arc_early_serial_write(struct console *con, const char *s,
+				   unsigned int n)
 {
 	struct earlycon_device *dev = con->data;