HBASE-17067 Procedure v2 - remove tryAcquire*Lock and use wait/wake to make; ADDENDUM Address review comment by Stephen Yuan Jiang

framework event based

hbase-procedure/src/main/java/org/apache/hadoop/hbase/procedure2/ProcedureExecutor.java

@@ -1096,8 +1096,8 @@ public class ProcedureExecutor<TEnvironment> {
             case LOCK_ACQUIRED:
                 break;
             case LOCK_YIELD_WAIT:
-              scheduler.yield(proc);
               procStack.unsetRollback();
+              scheduler.yield(proc);
               break;
             case LOCK_EVENT_WAIT:
               procStack.unsetRollback();