Ignore nonexistent /sys/class/leds/*/device/uevent in find_device_hardware_id
Ignore nonexistent /sys/class/leds/*/device/uevent in find_device_hardware_id

On a recent Raspberry Pi, "/sys/class/leds/default-on/device/uevent"
does not exist. Instead of failing with an exception, ignore it and
carry on.

ApproxEng/approxeng.input