MCS does not build on kvm-deb-xenial-x86

/home/buildbot/server/storage/columnstore/columnstore/utils/threadpool/threadpool.cpp:303:37: error: call of overloaded add(size_t&) is ambiguous

                 args.add(fMaxThreads);

                                     ^

In file included from /home/buildbot/server/storage/columnstore/columnstore/utils/threadpool/threadpool.cpp:27:0:

/home/buildbot/server/storage/columnstore/columnstore/utils/loggingcpp/messageobj.h:64:14: note: candidate: void logging::Message::Args::add(int)

         void add(int i);

              ^

/home/buildbot/server/storage/columnstore/columnstore/utils/loggingcpp/messageobj.h:68:14: note: candidate: void logging::Message::Args::add(uint64_t)

         void add(uint64_t i);

              ^

/home/buildbot/server/storage/columnstore/columnstore/utils/loggingcpp/messageobj.h:72:14: note: candidate: void logging::Message::Args::add(double)

         void add(double d);

              ^

diff --git a/utils/threadpool/threadpool.cpp b/utils/threadpool/threadpool.cpp

index da2b5f2..42d9166 100644

--- a/utils/threadpool/threadpool.cpp

+++ b/utils/threadpool/threadpool.cpp

@@ -298,9 +298,9 @@ uint64_t ThreadPool::invoke(const Functor_T& threadfunc)

                 logging::Message::Args args;

                 logging::Message message(5);

                 args.add("invoke: Blocked waiting for thread. Count ");

-                args.add(fThreadCount);

+                args.add((uint64_t)fThreadCount);

                 args.add("max ");

-                args.add(fMaxThreads);

+                args.add((uint64_t)fMaxThreads);

                 message.format( args );

                 logging::LoggingID lid(22);

                 logging::MessageLog ml(lid);