rcu: Fix hlist_bl_set_first_rcu() annotation

Abhi noticed that we were getting a complaint from the RCU subsystem
about access of an RCU protected list under the write side bit lock.
This commit adds additional annotation to check both the RCU read
lock and the write side bit lock before printing a message.

Reported by: Abhijith Das <adas@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
Tested-by: Abhijith Das <adas@redhat.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>