Core/Misc: Fix some static analysis issues

Fix some static analysis issues about uninitialized values in scripts.
Add spell id validation in Unit::SpellNonMeleeDamageLog() .

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

@@ -957,6 +957,8 @@ void Unit::CastSpell(GameObject* go, uint32 spellId, bool triggered, Item* castI
 uint32 Unit::SpellNonMeleeDamageLog(Unit* victim, uint32 spellID, uint32 damage)
 {
     SpellInfo const* spellInfo = sSpellMgr->GetSpellInfo(spellID);
+    if (!spellInfo)
+        return 0;
     SpellNonMeleeDamage damageInfo(this, victim, spellInfo->Id, spellInfo->SchoolMask);
     damage = SpellDamageBonusDone(victim, spellInfo, damage, SPELL_DIRECT_DAMAGE);
     damage = victim->SpellDamageBonusTaken(this, spellInfo, damage, SPELL_DIRECT_DAMAGE);

src/server/scripts/EasternKingdoms/AlteracValley/boss_balinda.cpp

@@ -60,6 +60,7 @@ public:
         {
             waterBoltTimer            = 3 * IN_MILLISECONDS;
             resetTimer                = 5 * IN_MILLISECONDS;
+            balindaGUID = 0;
         }
 
         void UpdateAI(uint32 diff) OVERRIDE

src/server/scripts/EasternKingdoms/BlackrockMountain/BlackrockSpire/boss_rend_blackhand.cpp

@@ -171,6 +171,7 @@ public:
             _Reset();
             gythEvent = false;
             victorGUID = 0;
+            portcullisGUID = 0;
         }
 
         void EnterCombat(Unit* /*who*/) OVERRIDE

src/server/scripts/EasternKingdoms/BlackrockMountain/BlackwingLair/instance_blackwing_lair.cpp

@@ -63,6 +63,7 @@ public:
         {
             // Razorgore
             EggCount = 0;
+            EggEvent = 0;
             RazorgoreTheUntamedGUID = 0;
             RazorgoreDoorGUID = 0;
             EggList.clear();

src/server/scripts/Northrend/CrusadersColiseum/TrialOfTheCrusader/boss_northrend_beasts.cpp

@@ -310,8 +310,6 @@ class npc_snobold_vassal : public CreatureScript
                 _targetGUID = 0;
                 _targetDied = false;
 
-                if (_instance)
-                    _bossGUID = _instance->GetData64(NPC_GORMOK);
                 //Workaround for Snobold
                 me->SetFlag(UNIT_FIELD_FLAGS, UNIT_FLAG_NON_ATTACKABLE | UNIT_FLAG_NOT_SELECTABLE);
             }
@@ -450,7 +448,6 @@ class npc_snobold_vassal : public CreatureScript
             private:
                 EventMap _events;
                 InstanceScript* _instance;
-                uint64 _bossGUID;
                 uint64 _targetGUID;
                 bool   _targetDied;
         };

src/server/scripts/Northrend/FrozenHalls/HallsOfReflection/halls_of_reflection.cpp

@@ -1185,6 +1185,7 @@ struct npc_gauntlet_trash : public ScriptedAI
 
     void Reset() OVERRIDE
     {
+        InternalWaveId = 0;
         me->CastSpell(me, SPELL_WELL_OF_SOULS, true);
         _events.Reset();
     }

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

@@ -514,6 +514,7 @@ class npc_gothik_minion : public CreatureScript
             npc_gothik_minionAI(Creature* creature) : CombatAI(creature)
             {
                 liveSide = IN_LIVE_SIDE(me);
+                gateClose = false;
             }
 
             bool liveSide;

src/server/scripts/Northrend/zone_zuldrak.cpp

@@ -457,6 +457,8 @@ public:
 
             void Reset() OVERRIDE
             {
+                _playerGUID = 0;
+                _getingredienttry = 0;
                 _events.ScheduleEvent(EVENT_TURN_TO_POT, urand(15000, 26000));
             }
 

src/server/scripts/Outland/Auchindoun/AuchenaiCrypts/boss_exarch_maladaar.cpp

@@ -68,6 +68,7 @@ public:
 
         void Reset() OVERRIDE
         {
+            myClass = CLASS_NONE;
             Class_Timer = 1000;
         }