tty: tty_ldisc: Remove the ret variable

The int variable ret does not receive the return value in this function.
It should be removed and returned 0 directly.
Signed-off-by: Li zeming <zeming@nfschina.com>
Reviewed-by: Jiri Slaby <jirislaby@kernel.org>
Link: https://lore.kernel.org/r/20230222202303.3195-1-zeming@nfschina.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/tty/tty_ldisc.c

@@ -58,7 +58,6 @@ static struct tty_ldisc_ops *tty_ldiscs[NR_LDISCS];
 int tty_register_ldisc(struct tty_ldisc_ops *new_ldisc)
 {
 	unsigned long flags;
-	int ret = 0;
 
 	if (new_ldisc->num < N_TTY || new_ldisc->num >= NR_LDISCS)
 		return -EINVAL;
@@ -67,7 +66,7 @@ int tty_register_ldisc(struct tty_ldisc_ops *new_ldisc)
 	tty_ldiscs[new_ldisc->num] = new_ldisc;
 	raw_spin_unlock_irqrestore(&tty_ldiscs_lock, flags);
 
-	return ret;
+	return 0;
 }
 EXPORT_SYMBOL(tty_register_ldisc);