gpio: gpio-mxc: gpio_set_wake_irq() use proper return values

Errors from enable_irq_wake() in gpio_set_wake_irq() were silently ignored.
Thus led to the problem that gpio_set_wake_irq() always returned
successfully, even if enable_irq_wake() returned an error.

Signed-off-by: Philipp Rosenberger <[e-mail]>
Signed-off-by: Linus Walleij <[e-mail]>

drivers/gpio/gpio-mxc.c

···
 	struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
 	struct mxc_gpio_port *port = gc->private;
 	u32 gpio_idx = d->hwirq;
+	int ret;
 
 	if (enable) {
 		if (port->irq_high && (gpio_idx >= 16))
-			enable_irq_wake(port->irq_high);
+			ret = enable_irq_wake(port->irq_high);
 		else
-			enable_irq_wake(port->irq);
+			ret = enable_irq_wake(port->irq);
 	} else {
 		if (port->irq_high && (gpio_idx >= 16))
-			disable_irq_wake(port->irq_high);
+			ret = disable_irq_wake(port->irq_high);
 		else
-			disable_irq_wake(port->irq);
+			ret = disable_irq_wake(port->irq);
 	}
 
-	return 0;
+	return ret;
 }
 
 static int mxc_gpio_init_gc(struct mxc_gpio_port *port, int irq_base)