It's not the responsibility of init_rootdomain() to free root_domain
allocated by alloc_rootdomain().
Signed-off-by: NLi Zefan <lizf@cn.fujitsu.com>
Reviewed-by: NPekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: NIngo Molnar <mingo@elte.hu>