fix a routing bug.

Venus/Venus_RT/Modules/AutoCycle.cs

@@ -1299,7 +1299,7 @@ namespace Venus_RT.Modules
                 {
                     ExchangeLLWafersWithPMs(ModuleName.LLA);
                 }
-                else if(IsLoadReadyForTM(ModuleName.LLB) && llaExchangeNumber > 0)
+                else if(IsLoadReadyForTM(ModuleName.LLB) && llbExchangeNumber > 0)
                 {
                     ExchangeLLWafersWithPMs(ModuleName.LLB);
                 }