doc: fix broken references

There are numerous broken references to Documentation files (in other
Documentation files, in comments, etc.). These broken references are
caused by typo's in the references, and by renames or removals of the
Documentation files. Some broken references are simply odd.

Fix these broken references, sometimes by dropping the irrelevant text
they were part of.

Signed-off-by: Paul Bolle <pebolle@tiscali.nl>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
diff --git a/fs/locks.c b/fs/locks.c
index 703f545..96b3398 100644
--- a/fs/locks.c
+++ b/fs/locks.c
@@ -60,7 +60,7 @@
  *
  *  Initial implementation of mandatory locks. SunOS turned out to be
  *  a rotten model, so I implemented the "obvious" semantics.
- *  See 'Documentation/mandatory.txt' for details.
+ *  See 'Documentation/filesystems/mandatory-locking.txt' for details.
  *  Andy Walker (andy@lysaker.kvaerner.no), April 06, 1996.
  *
  *  Don't allow mandatory locks on mmap()'ed files. Added simple functions to