Refactor lisp eval result printing

Refactor lisp eval result printing

* lisp/simple.el (eval-expression-print-format): Don't check
`standard-output' or `current-prefix-arg'.
(eval-expression-get-print-arguments): New function, centralizes
decision about how to print results of `eval-expression' and
`eval-last-sexp'.
(eval-expression):
* lisp/progmodes/elisp-mode.el (elisp--eval-last-sexp-print-value):
Use it.