gpiolib: Replace gpio_suffix_count with NULL-terminated array

There is no need to have and export the count variable for the array
in question. Instead, make it NULL-terminated.

Signed-off-by: Andy Shevchenko <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Bartosz Golaszewski <[e-mail]>

drivers/gpio/gpiolib.c

···
 static DEFINE_MUTEX(gpio_machine_hogs_mutex);
 static LIST_HEAD(gpio_machine_hogs);
 
-const char *const gpio_suffixes[] = { "gpios", "gpio" };
-const size_t gpio_suffix_count = ARRAY_SIZE(gpio_suffixes);
+const char *const gpio_suffixes[] = { "gpios", "gpio", NULL };
 
 static void gpiochip_free_hogs(struct gpio_chip *gc);
 static int gpiochip_add_irqchip(struct gpio_chip *gc,

drivers/gpio/gpiolib.h

···
 	return container_of(dev, struct gpio_device, dev);
 }
 
-/* gpio suffixes used for ACPI and device tree lookup */
+/* GPIO suffixes used for ACPI and device tree lookup */
 extern const char *const gpio_suffixes[];
-extern const size_t gpio_suffix_count;
 
 #define for_each_gpio_property_name(propname, con_id)					\
-	for (unsigned int __i = 0;							\
-	     __i < gpio_suffix_count && ({						\
-		     const char *__gs = gpio_suffixes[__i];				\
+	for (const char * const *__suffixes = gpio_suffixes;				\
+	     *__suffixes && ({								\
+		const char *__gs = *__suffixes;						\
 											\
 		if (con_id)								\
 			snprintf(propname, sizeof(propname), "%s-%s", con_id, __gs);	\
···
 			snprintf(propname, sizeof(propname), "%s", __gs);		\
 		1;									\
 	     });									\
-	     __i++)
+	     __suffixes++)
 
 /**
  * struct gpio_array - Opaque descriptor for a structure of GPIO array attributes