yast2-pkg-bindings-devel-doc.spec - do not use %name in %setup

"yast2-pkg-bindings-devel-doc" directory does not exist,
there is "yast2-pkg-bindings"
Merge pull request #9 from yast/devel_doc_spec_fix

yast2-pkg-bindings-devel-doc.spec - do not use %name in %setup