Fix fatigue bar vital

[TwelveEyes]

Fixes fatigueBar.Amount erroneously being set instead of fatigueBarGain.Amount.

[KABoissonneault]

Excuse me, can you explain what issue this is fixing exactly? What difference will the player observe? Is this only relevant for modders?
It does seem like it might be fixing something, but I'd like to know what to test before I can review this

[TwelveEyes]

It simply fixes the way the fatigue bar updates so it matches the health and magicka bars. Without this fix the fatigue bar change upon gain/loss is messed up. If you cast a Heal Fatigue spell you'll see the incorrect behavior.

https://github.com/Interkarma/daggerfall-unity/blob/master/Assets/Scripts/Game/UserInterface/HUDVitals.cs#L297
https://github.com/Interkarma/daggerfall-unity/blob/master/Assets/Scripts/Game/UserInterface/HUDVitals.cs#L344

[KABoissonneault]

Okay, so if I cast Heal Fatigue and compare it to other vitals, it should look "off". I would have liked more details but this will have to do I suppose.

[TwelveEyes]

It's quite obvious when there is a large gain/loss, just make sure EnableVitalsIndicators is enabled. I'll try to explain what it looks like anyway, since pointing out the discrepancy with the other vital bars wasn't enough.

On fatigue gain: The bar jumps to the new greater height, then smoothly animates the diff bar going down to the previous lower height. After that the bar jumps to the new greater height again.

On fatigue loss: The bar jumps to the new lower height, then smoothly animates the diff bar going up to the previous greater height. After that the bar jumps to the new lower height again.