serial: 8250_early: 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/8250/8250_early.c

@@ -37,7 +37,7 @@
 #include <asm/io.h>
 #include <asm/serial.h>
 
-static unsigned int __init serial8250_early_in(struct uart_port *port, int offset)
+static unsigned int serial8250_early_in(struct uart_port *port, int offset)
 {
 	int reg_offset = offset;
 	offset <<= port->regshift;
@@ -60,7 +60,7 @@ static unsigned int __init serial8250_early_in(struct uart_port *port, int offse
 	}
 }
 
-static void __init serial8250_early_out(struct uart_port *port, int offset, int value)
+static void serial8250_early_out(struct uart_port *port, int offset, int value)
 {
 	int reg_offset = offset;
 	offset <<= port->regshift;
@@ -89,7 +89,7 @@ static void __init serial8250_early_out(struct uart_port *port, int offset, int
 
 #define BOTH_EMPTY (UART_LSR_TEMT | UART_LSR_THRE)
 
-static void __init serial_putc(struct uart_port *port, int c)
+static void serial_putc(struct uart_port *port, int c)
 {
 	unsigned int status;
 
@@ -103,7 +103,7 @@ static void __init serial_putc(struct uart_port *port, int c)
 	}
 }
 
-static void __init early_serial8250_write(struct console *console,
+static void early_serial8250_write(struct console *console,
 					const char *s, unsigned int count)
 {
 	struct earlycon_device *device = console->data;