mpibenchmark: remove line breaks in MPI version string
For instance, the MPI version string of MPICH contains line breaks, which creates header lines not starting with a '#' and may cause errors in parsing scripts.
Prochaines maintenances programmées: lundi 06/05, lundi 03/06, lundi 01/07
Pour plus d'informations: https://doc-si.inria.fr/display/SU/Gitlab
For instance, the MPI version string of MPICH contains line breaks, which creates header lines not starting with a '#' and may cause errors in parsing scripts.