Fix bug#22891: wrong terminal width when a fringe width is zero.
When either fringe width is zero, Emacs reserved one column for a
continuation glyph. Terminal windows does not take this into
account when the frame is resized.
* lisp/window.el (window-adjust-process-window-size): Use
`window-max-chars-per-line' instead of `window-body-width'.
* lisp/term.el (term-window-width): Remove function. (It does the
same as `window-max-chars-per-line' but without recent bug fixes.)
(term-mode): Use `window-max-chars-per-line' instead of
`term-window-width'.
Backport
(cherry picked from commit
5b5403289888efe8783ae6a405845b925f544ec1)