org-capture: Fix bindings in header line

* lisp/org-capture.el (org-capture-mode): Display currently used
  bindings in header line.

lisp/org-capture.el

@@ -435,7 +435,9 @@ Turning on this mode runs the normal hook `org-capture-mode-hook'."
   nil " Rem" org-capture-mode-map
   (org-set-local
    'header-line-format
-   "Capture buffer.  Finish `C-c C-c', refile `C-c C-w', abort `C-c C-k'."))
+   (substitute-command-keys
+    "\\<org-capture-mode-map>Capture buffer.  Finish \\[org-capture-finalize], \
+refile \\[org-capture-refile], abort \\[org-capture-kill].")))
 (define-key org-capture-mode-map "\C-c\C-c" 'org-capture-finalize)
 (define-key org-capture-mode-map "\C-c\C-k" 'org-capture-kill)
 (define-key org-capture-mode-map "\C-c\C-w" 'org-capture-refile)