adding returncode to print command execution results

xtreemfs_client/div_util.py

@@ -55,6 +55,7 @@ def print_process_list(processes):
         print("command: " + str(process[0]))
         print("stout: " + str(process[1][0]))
         print("stderr: " + str(process[1][1]))
+        print("returncode: " + str(process[2]))
 
 
 """