[STUMP] stumpwm-mode.el, remove trailing newline added by echo(1)

[Anonymous]

stumpish always puts newline at the end. It makes some (interactive)
shells print prompt properly on the next line which is not needed for
`message' function. Try in a buffer with stumpwm-mode

  nil<C-x C-e>

would put NIL + newline in *Messages* buffer, e.g. unlike
eval-last-sexp in emacs-lisp-mode.

diff --git a/contrib/stumpwm-mode.el b/contrib/stumpwm-mode.el
index 404f528..c6a3ae4 100644
--- a/contrib/stumpwm-mode.el
+++ b/contrib/stumpwm-mode.el
@@ -48,6 +48,7 @@
                (call-process stumpwm-shell-program nil (current-buffer) nil
                              "eval"
                              s)
+               (delete-char -1)
                (buffer-string)))))
 
 (defun stumpwm-eval-defun ()