staging: dgnc: remove useless switch-case statements

The dgnc_tty_send_break() has a switch-case condition for msec.
It is no use except case -1.
Signed-off-by: Daeseok Youn <daeseok.youn@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/dgnc/dgnc_tty.c

@@ -1790,16 +1790,8 @@ static int dgnc_tty_send_break(struct tty_struct *tty, int msec)
 	if (!bd || bd->magic != DGNC_BOARD_MAGIC)
 		return -EIO;
 
-	switch (msec) {
-	case -1:
+	if (msec < 0)
 		msec = 0xFFFF;
-		break;
-	case 0:
-		msec = 0;
-		break;
-	default:
-		break;
-	}
 
 	spin_lock_irqsave(&ch->ch_lock, flags);