if you do...
if (abs(lastAnalogValue_potikka2 - cc_potikka2) > 6) {
MIDI.sendControlChange(17,cc_potikka2,2);
lastAnalogValue_potikka2 = cc_potikka2;
}
this will give you a gate which remains shut for very low fluctuations (noise) but then opens for large movements (when you actually move the fader/pot).
You effectively filter out the noise.