gpio: msm: make msm_gpio.summary_irq signed for error handling

There is a bug in msm_gpio_probe() where we do:

	msm_gpio.summary_irq = platform_get_irq(pdev, 0);
	if (msm_gpio.summary_irq < 0) {

The problem is that "msm_gpio.summary_irq" is unsigned so the error
handling doesn't work.  I've fixed it by making it signed.

Fixes: 43f6844 ('gpio: msm: Add device tree and irqdomain support for gpio-msm-v2')

Cc: stable@vger.kernel.org
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

drivers/gpio/gpio-msm-v2.c

@@ -102,7 +102,7 @@ struct msm_gpio_dev {
 	DECLARE_BITMAP(wake_irqs, MAX_NR_GPIO);
 	DECLARE_BITMAP(dual_edge_irqs, MAX_NR_GPIO);
 	struct irq_domain *domain;
-	unsigned int summary_irq;
+	int summary_irq;
 	void __iomem *msm_tlmm_base;
 };