Input: ps2mult - use guard notation when acquiring spinlock

Using guard notation makes the code more compact and error handling
more robust by ensuring that locks are released in all code paths
when control leaves critical section.

Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Dmitry Torokhov <[e-mail]>

drivers/input/serio/ps2mult.c

···
 	struct ps2mult *psm = serio_get_drvdata(mx_port);
 	struct ps2mult_port *port = serio->port_data;
 	bool need_escape;
-	unsigned long flags;
 
-	spin_lock_irqsave(&psm->lock, flags);
+	guard(spinlock_irqsave)(&psm->lock);
 
 	if (psm->out_port != port)
 		ps2mult_select_port(psm, port);
···
 
 	serio_write(mx_port, data);
 
-	spin_unlock_irqrestore(&psm->lock, flags);
-
 	return 0;
 }
 
···
 {
 	struct ps2mult *psm = serio_get_drvdata(serio->parent);
 	struct ps2mult_port *port = serio->port_data;
-	unsigned long flags;
 
-	spin_lock_irqsave(&psm->lock, flags);
+	guard(spinlock_irqsave)(&psm->lock);
+
 	port->registered = true;
-	spin_unlock_irqrestore(&psm->lock, flags);
 
 	return 0;
 }
···
 {
 	struct ps2mult *psm = serio_get_drvdata(serio->parent);
 	struct ps2mult_port *port = serio->port_data;
-	unsigned long flags;
 
-	spin_lock_irqsave(&psm->lock, flags);
+	guard(spinlock_irqsave)(&psm->lock);
+
 	port->registered = false;
-	spin_unlock_irqrestore(&psm->lock, flags);
 }
 
 static int ps2mult_create_port(struct ps2mult *psm, int i)
···
 
 static void ps2mult_reset(struct ps2mult *psm)
 {
-	unsigned long flags;
-
-	spin_lock_irqsave(&psm->lock, flags);
+	guard(spinlock_irqsave)(&psm->lock);
 
 	serio_write(psm->mx_serio, PS2MULT_SESSION_END);
 	serio_write(psm->mx_serio, PS2MULT_SESSION_START);
 
 	ps2mult_select_port(psm, &psm->ports[PS2MULT_KBD_PORT]);
-
-	spin_unlock_irqrestore(&psm->lock, flags);
 }
 
 static int ps2mult_connect(struct serio *serio, struct serio_driver *drv)
···
 {
 	struct ps2mult *psm = serio_get_drvdata(serio);
 	struct ps2mult_port *in_port;
-	unsigned long flags;
 
 	dev_dbg(&serio->dev, "Received %02x flags %02x\n", data, dfl);
 
-	spin_lock_irqsave(&psm->lock, flags);
+	guard(spinlock_irqsave)(&psm->lock);
 
 	if (psm->escape) {
 		psm->escape = false;
···
 	}
 
  out:
-	spin_unlock_irqrestore(&psm->lock, flags);
 	return IRQ_HANDLED;
 }