Merge remote-tracking branch 'mauro-exp/docbook3' into death-to-docbook

Mauro says:

This patch series convert the remaining DocBooks to ReST.

The first version was originally
send as 3 patch series:

   [PATCH 00/36] Convert DocBook documents to ReST
   [PATCH 0/5] Convert more books to ReST
   [PATCH 00/13] Get rid of DocBook

The lsm book was added as if it were a text file under
Documentation. The plan is to merge it with another file
under Documentation/security, after both this series and
a security Documentation patch series gets merged.

It also adjusts some Sphinx-pedantic errors/warnings on
some kernel-doc markups.

I also added some patches here to add PDF output for all
existing ReST books.

kernel/locking/mutex.c

@@ -227,9 +227,9 @@ static void __sched __mutex_lock_slowpath(struct mutex *lock);
  * (or statically defined) before it can be locked. memset()-ing
  * the mutex to 0 is not allowed.
  *
- * ( The CONFIG_DEBUG_MUTEXES .config option turns on debugging
- *   checks that will enforce the restrictions and will also do
- *   deadlock debugging. )
+ * (The CONFIG_DEBUG_MUTEXES .config option turns on debugging
+ * checks that will enforce the restrictions and will also do
+ * deadlock debugging)
  *
  * This function is similar to (but not equivalent to) down().
  */