These interfaces never did get used, so this commit removes them,
their rcutorture tests, and documentation referencing them.
Signed-off-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: NLai Jiangshan <laijs@cn.fujitsu.com>
Reviewed-by: NJosh Triplett <josh@joshtriplett.org>