Core/Auras: Replaced false with NULL since we are dealing with pointers

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

@@ -3143,7 +3143,7 @@ void Unit::DeMorph()
     SetDisplayId(GetNativeDisplayId());
 }
 
-Aura * Unit::_TryStackingOrRefreshingExistingAura(SpellEntry const * newAura, uint8 effMask, int32 *baseAmount, Item * castItem, uint64 casterGUID)
+Aura* Unit::_TryStackingOrRefreshingExistingAura(SpellEntry const* newAura, uint8 effMask, int32* baseAmount /*= NULL*/, Item* castItem /*= NULL*/, uint64 casterGUID /*= 0*/)
 {
     ASSERT(casterGUID);
     // passive and Incanter's Absorption and auras with different type can stack with themselves any number of times
@@ -3161,7 +3161,7 @@ Aura * Unit::_TryStackingOrRefreshingExistingAura(SpellEntry const * newAura, ui
             // extremely rare case
             // let's just recreate aura
             if (effMask != foundAura->GetEffectMask())
-                return false;
+                return NULL;
 
             // update basepoints with new values - effect amount will be recalculated in ModStackAmount
             for (uint8 i = 0; i < MAX_SPELL_EFFECTS; ++i)
@@ -3187,10 +3187,10 @@ Aura * Unit::_TryStackingOrRefreshingExistingAura(SpellEntry const * newAura, ui
 
             // try to increase stack amount
             foundAura->ModStackAmount(1);
-
             return foundAura;
         }
     }
+
     return NULL;
 }