[TMVA] CV modernise -- use auto when type is obvious
[TMVA] CV modernise -- use auto when type is obvious

karies/root,root-mirror/root,olifre/root,olifre/root,karies/root,root-mirror/root,karies/root,karies/root,root-mirror/root,root-mirror/root,olifre/root,root-mirror/root,karies/root,olifre/root,karies/root,olifre/root,olifre/root,karies/root,olifre/root,root-mirror/root,root-mirror/root,olifre/root,karies/root,karies/root,root-mirror/root,root-mirror/root,karies/root,root-mirror/root,karies/root,olifre/root,olifre/root,olifre/root,root-mirror/root