master ec5c723844: Fix error when describing menu items that don't have equivalent keys

[Po Lu]

branch: master
commit ec5c723844a56d43c7c82aa9a2eecf1ffca86c0b
Author: Po Lu <luangruo@yahoo.com>
Commit: Po Lu <luangruo@yahoo.com>

    Fix error when describing menu items that don't have equivalent keys
    
    * lisp/help-fns.el (help-fns--key-bindings): Never pass nil to
    insert.
---
 lisp/help-fns.el | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/lisp/help-fns.el b/lisp/help-fns.el
index 7858d88985..98a1b11e08 100644
--- a/lisp/help-fns.el
+++ b/lisp/help-fns.el
@@ -547,9 +547,9 @@ suitable file is found, return nil."
               (insert "\n"))
             (when menus
               (let ((start (point)))
-                (insert "It can "
-                        (and keys "also ")
-                        "be invoked from the menu: ")
+                (insert (concat "It can "
+                                (and keys "also ")
+                                "be invoked from the menu: "))
                 ;; FIXME: Should insert menu names instead of key
                 ;; binding names.
                 (help-fns--insert-bindings menus)