leds: multicolor: Use led_get_color_name() function

led_get_color_name() is a safer alternative to led_colors.

led-class-multicolor.c is the only external user of led_colors and its
removal allows unexporting the array.
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Link: https://lore.kernel.org/r/20240613-cros_ec-led-v3-2-500b50f41e0f@weissschuh.netSigned-off-by: Lee Jones <lee@kernel.org>

drivers/leds/led-class-multicolor.c

@@ -101,7 +101,7 @@ static ssize_t multi_index_show(struct device *dev,
 
 	for (i = 0; i < mcled_cdev->num_colors; i++) {
 		index = mcled_cdev->subled_info[i].color_index;
-		len += sprintf(buf + len, "%s", led_colors[index]);
+		len += sprintf(buf + len, "%s", led_get_color_name(index));
 		if (i < mcled_cdev->num_colors - 1)
 			len += sprintf(buf + len, " ");
 	}