Core/Misc: GCC build and warning fixes

src/server/game/AI/SmartScripts/SmartScript.cpp

@@ -2685,6 +2685,7 @@ void SmartScript::ProcessAction(SmartScriptHolder& e, Unit* unit, uint32 var0, u
                 break;
             }
         }
+            /* fallthrough */
         case SMART_ACTION_SET_CORPSE_DELAY:
         {
             ObjectList* targets = GetTargets(e, unit);