leds: Add warning printks in error paths
leds: Add warning printks in error paths

Add warning printks if led_trigger_register_simple() fails.

Signed-off-by: Richard Purdie <a03894c799ea916bd571ce8f12ed88f6fb3400f7@rpsys.net>

KristFoundation/Programs,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs