Fix maximal LED brightness

Since kernel commit a2cafdfd8cf5ad8adda6c0ce44a59f46431edf02, there are
257 possible values. 0 is off, 256 is full brightness, and 1 to 255 is
PWM control. Use full brightness here.

Change-Id: I4120ea587bc8ba593d47bdd8b76bb0217db600a5
diff --git a/package/czechlight-clearfog-leds/clearfog-test-leds.sh b/package/czechlight-clearfog-leds/clearfog-test-leds.sh
index 27e31ce..d09d8bc 100755
--- a/package/czechlight-clearfog-leds/clearfog-test-leds.sh
+++ b/package/czechlight-clearfog-leds/clearfog-test-leds.sh
@@ -12,7 +12,7 @@
         echo 0 > "/sys/class/leds/${LEDS[$PREVIOUS]}/brightness"
     fi
     if [[ $NUM -ne $LAST ]]; then
-        echo 255 > "/sys/class/leds/${LEDS[$NUM]}/brightness"
+        echo 256 > "/sys/class/leds/${LEDS[$NUM]}/brightness"
     fi
     sleep 0.3
 done