Change random generator to Bernoulli distribution

# Explain what has been changed

# Explain why this change is being made

# Provide links to any relevant tickets, articles or other resources

DRAMSys/simulator/src/controller/scheduler/SMS.cpp

@@ -1,4 +1,5 @@
 #include "SMS.h"
+#include <random>
 
 using namespace std;
 
@@ -72,12 +73,15 @@ bool SMS::batchFormation()
 void SMS::batchScheduler()
 {
   sc_time memClk = Configuration::getInstance().memSpec.clk;
+  std::default_random_engine generator;
+  std::bernoulli_distribution distribution((double) SJFprobability / 100.0);
+  bool isSJF;
+
   while (true)
   {
     wait(memClk);
 
-    srand(time(NULL));
-    bool isSJF = (rand() % 100) < SJFprobability;
+    isSJF = distribution(generator);
     if (!existReadyBatch())
     {
       // pick & drain a ready batch