rcu: Add synchronize_srcu_expedited() to the rcutorture test suite

rcu: Add synchronize_srcu_expedited() to the rcutorture test suite

Adds the "srcu_expedited" torture type, and also renames
sched_ops_sync to sched_sync_ops for consistency while we are in
this file.

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: <12565226353636-git-send-email->
Signed-off-by: Ingo Molnar <mingo@elte.hu>