Fixes the following cppcheck issues: examples/SecretKnockSensor/SecretKnockSensor.ino 305 variableScope 398 style The scope of the variable 'timeDiff' can be reduced. examples/SensebenderGatewaySerial/SensebenderGatewaySerial.ino 127 variableScope 398 style The scope of the variable 'led_state' can be reduced.