From: Miklos Szeredi <mszeredi@suse.cz>

Remove SLAB initialization entirely, as suggested by Bruce and Linus.
Allocate with __GFP_ZERO instead and only initialize list heads.
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>