Data argument to `signal` should be a list

Data argument to `signal` should be a list

* lisp/calendar/iso8601.el (iso8601-parse, iso8601-parse-date)
(iso8601-parse-time, iso8601-parse-zone, iso8601-parse-duration)
(iso8601-parse-interval):
* lisp/emacs-lisp/cl-lib.el (cl-values-list):
* lisp/emacs-lisp/comp.el (comp-decrypt-arg-list)
(comp-spill-lap-function, comp-emit-switch)
(comp-compute-dominator-tree, comp-final):
* lisp/image.el (image-type):
* lisp/image/exif.el (exif--parse-jpeg, exif--parse-exif-chunk)
(exif--parse-directory, exif--read-chunk, exif--read-number-be)
(exif--read-number-le):
* lisp/vc/vc.el (vc-default-last-change):
Wrap obvious non-list data arguments to `signal` in a list.