[SERIAL] Fix build errors and warnings

- Remove last usage of EVT_WRITE_WAKEUP
- Remove unused label + kfree()
- scratch3 now known as id3

drivers/serial/8250.c

@@ -379,7 +379,7 @@ static void autoconfig_has_efr(struct uart_8250_port *up)
 	if (id1 == 0x16 && id2 == 0xC9 &&
 	    (id3 == 0x50 || id3 == 0x52 || id3 == 0x54)) {
 		up->port.type = PORT_16C950;
-		up->rev = rev | (scratch3 << 8);
+		up->rev = rev | (id3 << 8);
 		return;
 	}
 	

drivers/serial/8250_pci.c

@@ -790,8 +790,6 @@ pci_init_one(struct pci_dev *dev, const struct pci_device_id *ent)
 
 	return 0;
 
- free:
-	kfree(priv);
  deinit:
 	if (board->init_fn)
 		board->init_fn(dev, 0);

drivers/serial/core.c

@@ -68,8 +68,6 @@ static void uart_wait_until_sent(struct tty_struct *tty, int timeout);
 void uart_write_wakeup(struct uart_port *port)
 {
 	struct uart_info *info = port->info;
-
-	set_bit(0, &info->event);
 	tasklet_schedule(&info->tlet);
 }
 
@@ -112,13 +110,12 @@ static void uart_tasklet_action(unsigned long data)
 	struct tty_struct *tty;
 
 	tty = info->tty;
-	if (!tty || !test_and_clear_bit(EVT_WRITE_WAKEUP, &info->event))
-		return;
-
-	if ((tty->flags & (1 << TTY_DO_WRITE_WAKEUP)) &&
-	    tty->ldisc.write_wakeup)
-		(tty->ldisc.write_wakeup)(tty);
-	wake_up_interruptible(&tty->write_wait);
+	if (tty) {
+		if ((tty->flags & (1 << TTY_DO_WRITE_WAKEUP)) &&
+		    tty->ldisc.write_wakeup)
+			tty->ldisc.write_wakeup(tty);
+		wake_up_interruptible(&tty->write_wait);
+	}
 }
 
 static inline void