Scripts/SmartAI: Some clean-up work:

- NULL -> nullptr
- Rename "AssistPlayerInCombat(who)" to "AssistPlayerInCombatAgainst(who)" to reflect what the method actually does
- Code style

No functionality was changed.

src/server/game/AI/ScriptedAI/ScriptedFollowerAI.cpp

@@ -63,7 +63,7 @@ void FollowerAI::AttackStart(Unit* who)
 //This part provides assistance to a player that are attacked by who, even if out of normal aggro range
 //It will cause me to attack who that are attacking _any_ player (which has been confirmed may happen also on offi)
 //The flag (type_flag) is unconfirmed, but used here for further research and is a good candidate.
-bool FollowerAI::AssistPlayerInCombat(Unit* who)
+bool FollowerAI::AssistPlayerInCombatAgainst(Unit* who)
 {
     if (!who || !who->GetVictim())
         return false;
@@ -104,7 +104,7 @@ void FollowerAI::MoveInLineOfSight(Unit* who)
 {
     if (me->HasReactState(REACT_AGGRESSIVE) && !me->HasUnitState(UNIT_STATE_STUNNED) && who->isTargetableForAttack() && who->isInAccessiblePlaceFor(me))
     {
-        if (HasFollowState(STATE_FOLLOW_INPROGRESS) && AssistPlayerInCombat(who))
+        if (HasFollowState(STATE_FOLLOW_INPROGRESS) && AssistPlayerInCombatAgainst(who))
             return;
 
         if (!me->CanFly() && me->GetDistanceZ(who) > CREATURE_Z_ATTACK_RANGE)