aufs: bugfix, support for the lock class name

Since lockdep_set_class() is a macro and the name string is generated
internally from its parameter, the same names were registered.
By this commit, which is rather verbose code, explicitly specify the
lock class with different names by removing a 'lc_idx' variable.

Signed-off-by: J. R. Okajima <hooanon05@yahoo.co.jp>
Merge branch 'aufs3.0/00base' into aufs3.0/01modular
Merge branch 'aufs3.0/01modular' into aufs3.0/30stdalone
Merge branch 'aufs3.0/30stdalone' into aufs3.0/39public
aufs3.0 20130204

Signed-off-by: J. R. Okajima <hooanon05@yahoo.co.jp>