Core/Misc: Multiple static analysis issues fixed (small optimizations and clear code)

src/server/game/Entities/Unit/Unit.cpp

@@ -3286,7 +3286,7 @@ void Unit::_AddAura(UnitAura* aura, Unit* caster)
     if (aura->IsSingleTarget())
     {
         ASSERT((IsInWorld() && !IsDuringRemoveFromWorld()) || (aura->GetCasterGUID() == GetGUID()) ||
-                (isBeingLoaded() && aura->HasEffectType(SPELL_AURA_CONTROL_VEHICLE)));
+                (IsLoading() && aura->HasEffectType(SPELL_AURA_CONTROL_VEHICLE)));
                 /* @HACK: Player is not in world during loading auras.
                  *        Single target auras are not saved or loaded from database
                  *        but may be created as a result of aura links (player mounts with passengers)