Don't use ellipses while cl-printing strings.

Don't use ellipses while cl-printing strings.

This fixes bug#65680.  The former use of print-length as a
bound on the length of the printed string was erroneous,
causing error messages preceding backtracees to get
unnecessarily truncated to 50 characters.

* lisp/emacs-lisp/cl-print.el (cl-print-object <string>):
Remove the substitution of ellipses for long strings.

* test/lisp/emacs-lisp/cl-print-tests.el
(cl-print-tests-ellipsis-string): Remove this test.