* hashcash.el (mail-add-payment): Replace mapcar called for effect with mapc.

* hashcash.el (mail-add-payment): Replace mapcar called for effect with mapc.

* imap.el (imap-open): Replace mapcar called for effect with mapc.
(top-level): Use mapc to set functions to be traced for debugging.

* legacy-gnus-agent.el (gnus-agent-convert-agentview): Replace mapcar called
 for effect with while loop.

* message.el (message-talkative-question): Replace mapcar called for effect
 with mapc.

* mm-util.el: Use mapc instead of mapcar to make compatible functions.
(mm-find-mime-charset-region, mm-find-charset-region): Replace mapcar called
 for effect with dolist.

* mml.el (mml-insert-mime): Replace mapcar called for effect with mapc.

* nndiary.el: Use dolist instead of mapcar to add diary headers to
 gnus-extra-headers and nnmail-extra-headers.

* nnimap.el (nnimap-request-update-info-internal): Replace mapcar called for
 effect with dolist.
(top-level): Use mapc to set functions to be traced for debugging.

* nnmail.el (nnmail-read-incoming-hook): Doc fix.
(nnmail-split-fancy-with-parent): Replace mapcar called for effect with dolist.

* nnmaildir.el (nnmaildir--delete-dir-files, nnmaildir-request-close): Replace
 mapcar called for effect with mapc.
(nnmaildir--scan, nnmaildir-request-scan, nnmaildir-retrieve-groups)
(nnmaildir-request-update-info, nnmaildir-request-delete-group)
(nnmaildir-retrieve-headers, nnmaildir-request-set-mark)
(nnmaildir-close-group): Replace mapcar called for effect with dolist.

* nnrss.el (nnrss-make-hash-index): Use gnus-remove-if instead of remove-if
 that's a cl function.

* webmail.el (webmail-debug): Replace mapcar called for effect with dolist.

* gnus-xmas.el (gnus-group-add-icon): Replace mapcar called for effect with
 mapc.