gpio: mockup: modify the return value check for devm_irq_sim_init()

As discussed with Marc Zyngier: irq_sim_init() and its devres variant
should return the base of the allocated interrupt range on success
rather than 0. This will be modified later - first, change the way
users handle the return value of these routines.
Signed-off-by: NBartosz Golaszewski <brgl@bgdev.pl>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

drivers/gpio/gpio-mockup.c

@@ -297,7 +297,7 @@ static int gpio_mockup_probe(struct platform_device *pdev)
 	}
 
 	rv = devm_irq_sim_init(dev, &chip->irqsim, gc->ngpio);
-	if (rv)
+	if (rv < 0)
 		return rv;
 
 	rv = devm_gpiochip_add_data(dev, &chip->gc, chip);