USB: serial: cp210x: use bool for registered flag

Use bool rather than u8 for the gpio-chip-registered flag.

Signed-off-by: Johan Hovold <johan@kernel.org>
diff --git a/drivers/usb/serial/cp210x.c b/drivers/usb/serial/cp210x.c
index 213ed38..ef7f1c0 100644
--- a/drivers/usb/serial/cp210x.c
+++ b/drivers/usb/serial/cp210x.c
@@ -219,7 +219,7 @@
 	struct gpio_chip	gc;
 	u8			config;
 	u8			gpio_mode;
-	u8			gpio_registered;
+	bool			gpio_registered;
 #endif
 	u8			partnum;
 };
@@ -1407,7 +1407,7 @@
 
 	result = gpiochip_add_data(&priv->gc, serial);
 	if (!result)
-		priv->gpio_registered = 1;
+		priv->gpio_registered = true;
 
 	return result;
 }
@@ -1418,7 +1418,7 @@
 
 	if (priv->gpio_registered) {
 		gpiochip_remove(&priv->gc);
-		priv->gpio_registered = 0;
+		priv->gpio_registered = false;
 	}
 }