Remove std::move.

Remove std::move.

According to clang:
src/xbt/xbt_replay.cpp:123:38: error: moving a temporary object prevents copy elision
      [-Werror,-Wpessimizing-move]
      simgrid::xbt::ReplayAction evt(std::move(simgrid::xbt::get_action(argv[0])));
                                     ^
src/xbt/xbt_replay.cpp:123:38: note: remove std::move call here
      simgrid::xbt::ReplayAction evt(std::move(simgrid::xbt::get_action(argv[0])));
                                     ^~~~~~~~~~                                 ~
1 error generated.