pinctrl: intel: ensure error return ret is initialized

In the (unlikely) event that community->ngpps is zero, or if every
gpp->gpio_base is less than zero, then an ininitialized value in
ret is returned by function intel_gpio_add_pin_ranges. Fix this by
ensuring ret is initialized to zero.  It's a moot point, but I think
it is worthwhile ensuring this corner case is fixed.

Detected by CoverityScan, CID#1462415 ("Uninitialized scalar variable")

Fixes: a60eac3239f0 ("pinctrl: intel: Allow custom GPIO base for pad groups")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Acked-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

drivers/pinctrl/intel/pinctrl-intel.c

@@ -1083,7 +1083,7 @@ static struct irq_chip intel_gpio_irqchip = {
 static int intel_gpio_add_pin_ranges(struct intel_pinctrl *pctrl,
 				     const struct intel_community *community)
 {
-	int ret, i;
+	int ret = 0, i;
 
 	for (i = 0; i < community->ngpps; i++) {
 		const struct intel_padgroup *gpp = &community->gpps[i];