Core/Movement: Use SetWalk(true/false) instead of AddUnit/RemoveUnit.

src/server/scripts/Outland/HellfireCitadel/HellfireRamparts/boss_vazruden_the_herald.cpp

@@ -146,7 +146,7 @@ class boss_nazan : public CreatureScript
                         BellowingRoar_Timer = 6000;
                         ConeOfFire_Timer = 12000;
                         me->RemoveUnitMovementFlag(MOVEMENTFLAG_LEVITATING);
-                        me->AddUnitMovementFlag(MOVEMENTFLAG_WALKING);
+                        me->SetWalk(true);
                         me->GetMotionMaster()->Clear();
                         if (Unit* victim = SelectTarget(SELECT_TARGET_NEAREST, 0))
                             me->AI()->AttackStart(victim);

src/server/scripts/Outland/HellfireCitadel/ShatteredHalls/boss_warchief_kargath_bladefist.cpp

@@ -95,7 +95,7 @@ class boss_warchief_kargath_bladefist : public CreatureScript
                 removeAdds();
 
                 me->SetSpeed(MOVE_RUN, 2);
-                me->RemoveUnitMovementFlag(MOVEMENTFLAG_WALKING);
+                me->SetWalk(false);
 
                 summoned = 2;
                 InBlade = false;