aufs: bugfix, get a removed dentry from an inode

In aufs, there are several places getting a dentry from an inode.
It can happen that all names are unlinked and only the inode is still
alive. In this case, d_find_alias() doesn't return any dentry and aufs
cannot find the dentry, so it simply returns an error. It is ok in most
cases. but in some cases, aufs should search a dentry even if it was
unlinked. For these cases, replace them by d_find_any_alias() which can
return a removed dentry.

This problem was found by Andrew Vagin using inotify00 test program in
http://git.criu.org/?p=criu.git;a=blob;f=test/zdtm/live/static/inotify00.c;h=587408cda5bd3bb4e3da47a657ee1258635a1ccd;hb=HEAD

Reported-by: Andrew Vagin <shpagin@users.sf.net>
Bug-registered-at: Ticket 20 <20@bugs.aufs.p.re.sf.net>
Signed-off-by: J. R. Okajima <hooanon05g@gmail.com>
aufs: debug, more lockdep_off()

There are several characteristics in aufs, includeing the callee of VFS
(as an orrinary fs) and the caller of VFS for branch fs.
Re-entering VFS layer, VFS acquires vairous locks in the same lock
class. It causes the unnecessary lockdep warnings. As long as aufs
behaves correctly, those messages are false postive.
During the test of previous commit
	2014-08-31 aufs: bugfix, get a removed dentry from an inode
I saw the same scenario in fsnotify module since it is called in VFS.
It was triggered by struct fsnotify_group->mark_mutex.

Signed-off-by: J. R. Okajima <hooanon05g@gmail.com>
Merge remote-tracking branch 'aufs3-standalone/aufs3.9/00base' into aufs3.9/10static
Merge branch 'aufs3.9/10static' into aufs3.9/11proc_map
Merge branch 'aufs3.9/00base' into aufs3.10/00base
Merge branch 'aufs3.9/10static' into aufs3.10/10static
Merge remote-tracking branch 'aufs3-standalone/aufs3.10/00base' into aufs3.10/10static
Merge branch 'aufs3.9/11proc_map' into aufs3.10/11proc_map
Merge branch 'aufs3.10/10static' into aufs3.10/11proc_map
Merge branch 'aufs3.10/00base' into aufs3.11/00base
Merge branch 'aufs3.11/00base' into aufs3.12/00base
Merge branch 'aufs3.12/00base' into aufs3.12.x/00base
Merge branch 'aufs3.10/10static' into aufs3.11/10static
Merge remote-tracking branch 'aufs3-standalone/aufs3.11/00base' into aufs3.11/10static
Merge branch 'aufs3.10/11proc_map' into aufs3.11/11proc_map
Merge branch 'aufs3.11/10static' into aufs3.11/11proc_map
Merge branch 'aufs3.11/10static' into aufs3.12/10static
Merge remote-tracking branch 'aufs3-standalone/aufs3.12/00base' into aufs3.12/10static
Merge branch 'aufs3.11/11proc_map' into aufs3.12/11proc_map
Merge branch 'aufs3.12/10static' into aufs3.12/11proc_map