Don't infinite loop in map-y-or-n-p if at the end of kmacro

Don't infinite loop in map-y-or-n-p if at the end of kmacro

Previously, if map-y-or-n-p got -1 from read-event (indicating no
input due to the end of a keyboard macro), it would just infinite
loop.

Now it behaves like other commands which use read-event/read-char/etc,
and just errors when we try to look up -1 in our keymap and find
nothing.

Also, just for the sake of users, print a slightly prettier message
when this happens.

* lisp/emacs-lisp/map-ynp.el (map-y-or-n-p): Don't loop if we reach
the end of a keyboard macro.  (Bug#67046)