leds-pca963x: Fix device tree parsing

A malformed device tree could lead into a segmentation fault if the reg
value of a led is bigger than the number of leds.

A valid device tree could have only information about the last led of the
chip. Fix the device tree parsing to handle those cases.

Signed-off-by: Ricardo Ribalda Delgado <[e-mail]>
Signed-off-by: Bryan Wu <[e-mail]>

drivers/leds/leds-pca963x.c

···
 		u32 reg;
 		int res;
 
+		res = of_property_read_u32(child, "reg", &reg);
+		if ((res != 0) || (reg >= chip->n_leds))
+			continue;
 		led.name =
 			of_get_property(child, "label", NULL) ? : child->name;
 		led.default_trigger =
 			of_get_property(child, "linux,default-trigger", NULL);
-		res = of_property_read_u32(child, "reg", &reg);
-		if (res != 0)
-			continue;
 		pca963x_leds[reg] = led;
 	}
 	pdata = devm_kzalloc(&client->dev,
···
 		return ERR_PTR(-ENOMEM);
 
 	pdata->leds.leds = pca963x_leds;
-	pdata->leds.num_leds = count;
+	pdata->leds.num_leds = chip->n_leds;
 
 	/* default to open-drain unless totem pole (push-pull) is specified */
 	if (of_property_read_bool(np, "nxp,totem-pole"))