Core/Misc: Fix issues reported by static analysis

(cherry picked from commit 3e73ba9da5)

src/server/game/AI/PlayerAI/PlayerAI.cpp

@@ -157,7 +157,7 @@ void SimpleCharmedPlayerAI::UpdateAI(const uint32 /*diff*/)
         for (Player::AuraEffectList::const_iterator iter = auras.begin(); iter != auras.end(); ++iter)
             if ((*iter)->GetCasterGUID() == charmer->GetGUID() && (*iter)->GetBase()->IsPermanent())
             {
-                me->Kill(me);
+                me->KillSelf();
                 return;
             }
     }

src/server/scripts/Northrend/Naxxramas/boss_gluth.cpp

@@ -393,6 +393,7 @@ public:
             GluthGUID = creature->GetInstanceScript()->GetGuidData(DATA_GLUTH);
 
             DoCast(me, SPELL_INFECTED_WOUND);
+            timer = 0;
             state = STATE_ZOMBIE_NORMAL;
         }
 

src/server/scripts/Outland/CoilfangReservoir/TheSlavePens/boss_ahune.cpp

@@ -542,6 +542,7 @@ public:
         npc_earthen_ring_flamecallerAI(Creature* creature) : ScriptedAI(creature)
         {
             _instance = me->GetInstanceScript();
+            _mySpot = 0;
         }
 
         void Reset() override