Input: gamecon - use guard notation when acquiring mutex

Using guard notation makes the code more compact and error handling
more robust by ensuring that mutexes 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/joystick/gamecon.c

···
 static int gc_open(struct input_dev *dev)
 {
 	struct gc *gc = input_get_drvdata(dev);
-	int err;
 
-	err = mutex_lock_interruptible(&gc->mutex);
-	if (err)
-		return err;
+	scoped_guard(mutex_intr, &gc->mutex) {
+		if (!gc->used++) {
+			parport_claim(gc->pd);
+			parport_write_control(gc->pd->port, 0x04);
+			mod_timer(&gc->timer, jiffies + GC_REFRESH_TIME);
+		}
 
-	if (!gc->used++) {
-		parport_claim(gc->pd);
-		parport_write_control(gc->pd->port, 0x04);
-		mod_timer(&gc->timer, jiffies + GC_REFRESH_TIME);
+		return 0;
 	}
 
-	mutex_unlock(&gc->mutex);
-	return 0;
+	return -EINTR;
 }
 
 static void gc_close(struct input_dev *dev)
 {
 	struct gc *gc = input_get_drvdata(dev);
 
-	mutex_lock(&gc->mutex);
+	guard(mutex)(&gc->mutex);
+
 	if (!--gc->used) {
 		del_timer_sync(&gc->timer);
 		parport_write_control(gc->pd->port, 0x00);
 		parport_release(gc->pd);
 	}
-	mutex_unlock(&gc->mutex);
 }
 
 static int gc_setup_pad(struct gc *gc, int idx, int pad_type)