Tweak doc of `analyze-text-conversion` vs `post-self-insert-hook`

* lisp/simple.el (analyze-text-conversion): Fix typo.

* lisp/progmodes/cc-mode.el (c-initialize-cc-mode): Add comment about
`post-text-conversion-hook`.
2 jobs for master in 18 minutes and 40 seconds (queued for 10 seconds)
Status Job ID Name Coverage
  Normal
failed #78186
test-lisp-inotify

00:18:40

passed #78187
test-lisp-progmodes-inotify

00:17:20

 
Name Stage Failure
failed
test-lisp-inotify Normal
$ find ${test_name} ! \( -name "*.log" -o -name ${EMACS_TEST_JUNIT_REPORT} \) -type f -delete
$ find ${test_name} -type d -depth -exec rmdir {} + 2>/dev/null
Uploading artifacts...
test-lisp-inotify-213d30b3/: found 119 matching files
Uploading artifacts to coordinator... ok
id=78186 responseStatus=201 Created token=xxRxAR86
Uploading artifacts...
test-lisp-inotify-213d30b3/junit-test-report.xml: found 1 matching files

Uploading artifacts to coordinator... ok
id=78186 responseStatus=201 Created token=xxRxAR86
ERROR: Job failed: exit code 2