rcu: Add synchronize_srcu_expedited() to the documentation

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Acked-by: Josh Triplett <josh@joshtriplett.org>
Reviewed-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Cc: dipankar@in.ibm.com
Cc: mathieu.desnoyers@polymtl.ca
Cc: dvhltc@us.ibm.com
Cc: niv@us.ibm.com
Cc: peterz@infradead.org
Cc: rostedt@goodmis.org
Cc: Valdis.Kletnieks@vt.edu
Cc: dhowells@redhat.com
Cc: avi@redhat.com
Cc: mtosatti@redhat.com
LKML-Reference: <12565226354176-git-send-email->
Signed-off-by: Ingo Molnar <mingo@elte.hu>

Documentation/RCU/whatisRCU.txt

@@ -830,7 +830,7 @@ sched:	Critical sections	Grace period		Barrier
 SRCU:	Critical sections	Grace period		Barrier
 
 	srcu_read_lock		synchronize_srcu	N/A
-	srcu_read_unlock
+	srcu_read_unlock	synchronize_srcu_expedited
 
 SRCU:	Initialization/cleanup
 	init_srcu_struct