707702a4478960776d455e9fdec702349b74886d Revert "preprocessor: replace oo_.exo_steady_state with steady_state_x, #825"

================================ DYNARE MAKE CHECK MATLAB RESULTS ================================ | TOTAL: 502 | PASS: 495 | FAIL: 4 | XFAIL: 3 | XPASS: 0 | LIST OF FAILED TESTS: | * simul/Solow_no_varexo.mod | * kalman_filter_smoother/check_variable_dimensions/fs2000_ML.mod | * deterministic_simulations/homotopy.mod | * forecast/Hansen_exo_det_forecast.mod

================================ DYNARE MAKE CHECK OCTAVE RESULTS ================================ | TOTAL: 496 | PASS: 488 | FAIL: 5 | XFAIL: 3 | XPASS: 0 | LIST OF FAILED TESTS: | * simul/Solow_no_varexo.mod | * kalman_filter_smoother/check_variable_dimensions/fs2000_ML.mod | * deterministic_simulations/homotopy.mod | * forecast/Hansen_exo_det_forecast.mod | * ../matlab/lyapunov_symm.m#1

A full log can be found on karaba in '/tmp/dynare-master-check-dRI84uBOYe.log'.