Fix spurrious issue with same name twice in branch name.

Code that was specific to TBranchSTL was applied to all
branches leading to spurrious removal of part of the branch
name if the same data member name was repeated twice in
the hierarchy.   This fixes ROOT-5628.
In CallCloseFiles do not inadvertently create the TROOT object.

This fixes the end of programs (eg. stressVector) that link against
libCore but do not use TROOT.