[PATCH] jbd2: rename slab

jbd and jbd2 currently use the same slab names which must be unique.  The
patch below just renames jbd2's slabs.

Signed-off-by: Johann Lombardi <johann.lombardi@bull.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>