tracing: remove recursive test from ring_buffer_event_discard

The ring_buffer_event_discard is not tied to ring_buffer_lock_reserve.
It can be called inside or outside the reserve/commit. Even if it
is called inside the reserve/commit the commit part must also be called.

Only ring_buffer_discard_commit can be used as a replacement for
ring_buffer_unlock_commit.

This patch removes the trace_recursive_unlock from ring_buffer_event_discard
since it would be the wrong place to do so.

[Impact: prevent breakage in trace recursive testing ]

Cc: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>

kernel/trace/ring_buffer.c

@@ -1667,7 +1667,6 @@ static inline void rb_event_discard(struct ring_buffer_event *event)
 void ring_buffer_event_discard(struct ring_buffer_event *event)
 {
 	rb_event_discard(event);
-	trace_recursive_unlock();
 }
 EXPORT_SYMBOL_GPL(ring_buffer_event_discard);