inotify: remove debug code

The inotify debugging code is supposed to verify that the
DCACHE_INOTIFY_PARENT_WATCHED scalability optimisation does not result in
notifications getting lost nor extra needless locking generated.

Unfortunately there are also some races in the debugging code.  And it isn't
very good at finding problems anyway.  So remove it for now.

Signed-off-by: Nick Piggin <npiggin@suse.de>
Cc: Robert Love <rlove@google.com>
Cc: John McCutchan <ttb@tentacle.dhs.org>
Cc: Jan Kara <jack@ucw.cz>
Cc: Yan Zheng <yanzheng@21cn.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>