OPT: msct_register_landmark: fixed issues with QC output
OPT: msct_register_landmark: fixed issues with QC output

Former-commit-id: 80d02406cec6b86549e1005ed6b45a56efaaf5e5
Former-commit-id: 3faf4829d6440049470d24646f72f05b69bf92cc
3324fr/spinalcordtoolbox,3324fr/spinalcordtoolbox,3324fr/spinalcordtoolbox,3324fr/spinalcordtoolbox,3324fr/spinalcordtoolbox,3324fr/spinalcordtoolbox,3324fr/spinalcordtoolbox