Commit 
af906faabcf91eb1 ("Input: gpio_keys - fix warning regarding uninitialized
'irq' variable") introduced the following build warning:
drivers/input/keyboard/gpio_keys.c:625:16: warning: 'button' may be used uninitialized in this function [-Wmaybe-uninitialized]
Move the 'button' initialization to a proper location to avoid such warning.
Reported-by: Olof's autobuilder <build@lixom.net>
Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
 
                int gpio = -1;
                enum of_gpio_flags flags;
 
+               button = &pdata->buttons[i++];
+
                if (!of_find_property(pp, "gpios", NULL)) {
                        button->irq = irq_of_parse_and_map(pp, 0);
                        if (button->irq == 0) {
+                               i--;
                                pdata->nbuttons--;
                                dev_warn(dev, "Found button without gpios or irqs\n");
                                continue;
                        }
                }
 
-               button = &pdata->buttons[i++];
-
                button->gpio = gpio;
                button->active_low = flags & OF_GPIO_ACTIVE_LOW;