serial: sunzilog: Return proper error code from console ->setup() hook

For unifying console ->setup() handling, which is poorly documented,
return error code, rather than non-zero arbitrary number.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Petr Mladek <pmladek@suse.com>
Link: https://lore.kernel.org/r/20200618164751.56828-4-andriy.shevchenko@linux.intel.com

Author: andy-shev

drivers/tty/serial/sunzilog.c

@@ -1221,7 +1221,7 @@ static int __init sunzilog_console_setup(struct console *con, char *options)
 	int baud, brg;
 
 	if (up->port.type != PORT_SUNZILOG)
-		return -1;
+		return -EINVAL;
 
 	printk(KERN_INFO "Console: ttyS%d (SunZilog zs%d)\n",
 	       (sunzilog_reg.minor - 64) + con->index, con->index);