fix(eval): type error in +emacs-lisp-eval

When evaluating from a buffer not visiting any file, file-truename would
error out since the argument it was fed is nil.

Fix: #6181
Close: #6404
Ref: 7290f85cfd
Co-authored-by: Yoav Marco <ymarco@users.noreply.github.com>

modules/lang/emacs-lisp/autoload.el

@@ -12,7 +12,8 @@ to a pop up buffer."
     (condition-case-unless-debug e
         (let ((result
                (let* ((buffer-file-name (buffer-file-name (buffer-base-buffer)))
-                      (buffer-file-truename (file-truename buffer-file-name))
+                      (buffer-file-truename
+                       (and buffer-file-name (file-truename buffer-file-name)))
                       (doom--current-module
                        (ignore-errors (doom-module-from-path buffer-file-name)))
                       (debug-on-error t))