docbook: warn on unused doc entries
When you don't use !E or !I but only !F, then it's very easy to miss
including some functions, structs etc. in documentation. To help
finding which ones were missed, allow printing out the unused ones as
warnings.
For example, using this on mac80211 yields a lot of warnings like this:
Warning: didn't use docs for DOC: mac80211 workqueue
Warning: didn't use docs for ieee80211_max_queues
Warning: didn't use docs for ieee80211_bss_change
Warning: didn't use docs for ieee80211_bss_conf
when generating the documentation for it.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>