lantiq: diag - switch off the power led on failsafe

This patch is a follow up to commit 4cf3fd4 "add support for indicating
the boot state using three leds".

At the time of writing the patch, I wasn't aware that it's possible to
switch info failsafe after boot (factory reset).

Enabling the failsafe led without disabling the running led causes an
unexpected led colour on devices using a single multicolour led to
indicate the boot state.

Signed-off-by: Mathias Kresin <dev@kresin.me>

target/linux/lantiq/base-files/etc/diag.sh

@@ -17,6 +17,10 @@ set_state() {
 		;;
 	failsafe)
 		status_led_off
+		[ -n "$running" ] && {
+			status_led="$running"
+			status_led_off
+		}
 		status_led="$failsafe"
 		status_led_blink_failsafe
 		;;