workqueue: prepare for more tracepoints

Define workqueue_work event class and use it for workqueue_execute_end
trace point.  Also, move trace/events/workqueue.h include downwards
such that all struct definitions are visible to it.  This is to
prepare for more tracepoints and doesn't cause any functional change.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
diff --git a/include/trace/events/workqueue.h b/include/trace/events/workqueue.h
index 49682d7..ec9d724 100644
--- a/include/trace/events/workqueue.h
+++ b/include/trace/events/workqueue.h
@@ -7,6 +7,23 @@
 #include <linux/tracepoint.h>
 #include <linux/workqueue.h>
 
+DECLARE_EVENT_CLASS(workqueue_work,
+
+	TP_PROTO(struct work_struct *work),
+
+	TP_ARGS(work),
+
+	TP_STRUCT__entry(
+		__field( void *,	work	)
+	),
+
+	TP_fast_assign(
+		__entry->work		= work;
+	),
+
+	TP_printk("work struct %p", __entry->work)
+);
+
 /**
  * workqueue_execute_start - called immediately before the workqueue callback
  * @work:	pointer to struct work_struct
@@ -38,24 +55,13 @@
  *
  * Allows to track workqueue execution.
  */
-TRACE_EVENT(workqueue_execute_end,
+DEFINE_EVENT(workqueue_work, workqueue_execute_end,
 
 	TP_PROTO(struct work_struct *work),
 
-	TP_ARGS(work),
-
-	TP_STRUCT__entry(
-		__field( void *,	work	)
-	),
-
-	TP_fast_assign(
-		__entry->work		= work;
-	),
-
-	TP_printk("work struct %p", __entry->work)
+	TP_ARGS(work)
 );
 
-
 #endif /*  _TRACE_WORKQUEUE_H */
 
 /* This part must be outside protection */