led: triggers: fix crash on disabling "default-on" trigger
Here is a sample crash log on Ritmix RZX-50:
barebox:/ trigger
0: panic
1: heartbeat
2: net rx
3: net tx
4: net
5: default on (led 0)
barebox:/ trigger -d 5
...
Ooops, TLB miss on store!
Signed-off-by: Antony Pavlov <antonynpavlov@gmail.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>