rcu: Document RCU_INIT_POINTER()'s lack of ordering guarantees
rcu: Document RCU_INIT_POINTER()'s lack of ordering guarantees

Although rcu_assign_pointer() provides ordering guarantees,
RCU_INIT_POINTER() does not.  This commit makes that explicit
in the docbook comment header.

Reported-by: Lai Jiangshan <4c9eb49378914b743bdd32292c04df29b820d73e@cn.fujitsu.com>
Signed-off-by: Paul E. McKenney <1e0ce936bb9b355d257bf5790d2513c3f28be22b@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <c028c213ed5efcf30c3f4fc7361dbde0c893c5b7@joshtriplett.org>

KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs