LEDOutput.cpp: Checks against negativity on unsigned values

[HowManyOliversAreThere]

There are multiple sections of code where a value is checked for negativity, when the value is an unsigned type (such as the line if (inTimeMillis < 0){inTimeMillis = abs(inTimeMillis);}).

It would be a very minor performance gain if these checks were simply removed (as they serve no purpose in the current code).

[seanlano]

Fair point, I will review this.