Signal error on newline in internal--format-docstring-line

Signal error on newline in internal--format-docstring-line

* lisp/subr.el (internal--format-docstring-line): Signal error
when trying to fill a line containing a newline.

* lisp/cedet/semantic/decorate/mode.el
(define-semantic-decoration-style):
* lisp/emacs-lisp/easy-mmode.el (define-globalized-minor-mode):
Don't pass newlines to 'internal--format-docstring-line'.