lisp/ob.el: Fix org-babel-result-regexp to match users
* lisp/ob.el (org-babel-result-regexp): Use non-shy group around
org-babel-data-names.
By default regexp-opt returns a shy group around its arguments. But
users of org-babel-result-regexp expect the third match-string to
contain the hash. With a shy group, the second match-string contains
the hash.