gpio: omap: irq_startup() must not return error codes

The irq_startup() method returns an unsigned int, but in __irq_startup()
it is assigned to an int.  However, nothing checks for errors, so any
error that is returned is ignored.

Remove the check for GPIO-input mode and the error return.

Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: Grygorii Strashko <grygorii.strashko@ti.com>
Tested-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

drivers/gpio/gpio-omap.c

@@ -635,18 +635,13 @@ static unsigned int omap_gpio_irq_startup(struct irq_data *d)
 
 	if (!LINE_USED(bank->mod_usage, offset))
 		omap_set_gpio_direction(bank, offset, 1);
-	else if (!omap_gpio_is_input(bank, offset))
-		goto err;
 	omap_enable_gpio_module(bank, offset);
 	bank->irq_usage |= BIT(offset);
 
 	raw_spin_unlock_irqrestore(&bank->lock, flags);
 	omap_gpio_unmask_irq(d);
 
 	return 0;
-err:
-	raw_spin_unlock_irqrestore(&bank->lock, flags);
-	return -EINVAL;
 }
 
 static void omap_gpio_irq_shutdown(struct irq_data *d)