m68k/amiserial: fix fallout of tty break handling rework

commit 9e98966c (tty: rework break handling)
forgot to update one exit point of rs_break() in the Amiga serial driver.
Signed-off-by: NGeert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

drivers/char/amiserial.c

@@ -1254,7 +1254,7 @@ static int rs_break(struct tty_struct *tty, int break_state)
 	unsigned long flags;
 
 	if (serial_paranoia_check(info, tty->name, "rs_break"))
-		return;
+		return -EINVAL;
 
 	local_irq_save(flags);
 	if (break_state == -1)