Commit 4f21eb03 broke the generation of non-flat vcxprojs.
XTreeNode passes filter names to outputFileConfigs that have
the source subdirectory suffixed (e.g. "Generated Files\subdir").
Function filterByName must be called with the substring before the
backslash.
Change-Id: Ic259e6316ab0727828773b13e0d8ad0cc7f0808f
Task-number: QTBUG-41746
Reviewed-by: Oswald Buddenhagen <oswald.buddenhagen@theqtcompany.com>
Reviewed-by: Joerg Bornemann <joerg.bornemann@theqtcompany.com>